Have you ever wondered about the origins of this intriguing saying or how to use it effectively in your daily conversations? This article explores the historical context of “putting the kibosh” and its various interpretations across different scenarios.

Have you ever heard someone say they were going to “put the kibosh” on something? Did you ever wonder what they meant, or what a “kibosh” is?

Believe it or not, this has been a long-standing mystery of the English language. Multiple theories have been proposed, but none could be proven. Recently, however, three scholars seem to have gotten to the bottom of it. (2)

Here’s the story.

‘To put the kibosh’ on means to shut something down

First of all, to “put the kibosh” on something means you’re shutting it down. You’re putting the lid on a plan before it can take off. Or you’re stopping an activity that’s already underway.

For example, parents might “put the kibosh” on their teenager’s plan to throw a wild party. Or a librarian might “put the kibosh” on patrons who are munching on burgers and fries while they’re handling books.

This word first showed up in print in 1826, in a London newspaper. And not too long after, etymologists started speculating about where it came from.

5 (probably debunked) theories on the origin of ‘kibosh’

Theory number one was that “kibosh” was of Yiddish origin; that it was related to the Hebrew word “kāḇaš,” meaning to subject, subdue, or tread down. (9)

Theory two was that it was related to the Turkish word “bosh,” meaning “empty or worthless.” That word came into fashion around the same time that “kibosh” did, in the 1830s. It appeared in a popular romance titled “opens in a new windowAyesha, Maid of Kars,” that told of the intrigues of female life in Turkey. (7,8,9)

To see this connection, you can image a stodgy English gentleman saying “Bosh! Stuff and nonsense!” about the butler’s plan to serve bread and butter with tea, instead of cake. And the gentleman saying he would “put the kibosh” on that plan straightaway.

Theory three is that “kibosh” comes from the Gaelic “caidhp bháis,” meaning “coif of death.” This referred to various things: the hood an executioner wore when he mounted the scaffold; the head covering a judge wore when pronouncing the death sentence; or the cap put on a body before it was buried.

It was also connected to a gruesome form of torture known as a “pitch-cap,” in which a hat filled with boiling tar was placed on someone’s head. This cruel technique was used by the English military during the Irish rebellion of 1798. Game of Thrones fans will see an analogy between the pitch-cap and the “golden crown” that Khal Drogo placed on Viserys’ head. (5,6,9)

Theory four is that “kibosh” comes from the French word “caboche,” an informal word for head, and the English word “caboshe” that came from it. To “caboshe” means to cut off the head of a deer right behind the horns—not keeping any neck at all! You could see how this violent verb could be extended to mean beheading any sort of idea at all.  (5,6,9)

Theory five is that this word came from a tool that shoemakers used when making clogs. Their “kibosh” was an “iron bar about a foot long that, when hot, [was] used to soften and smooth leather.” A long, heated, metal bar would indeed be effective at kiboshing just about anything. Nonetheless, the scholar who first proposed this theory has pretty much admitted he no longer thinks it is correct. (1,5,6,9)

The current theory on the origin of ‘kibosh’: it’s related to an Arabic word for ‘whip’

Theory six—and the one that now seems to be most reliable— is that “kibosh” can be traced to the Arabic word “qurbāsh,” a whip made of hide. (2) It was sometimes made of hippopotamus or rhinoceros hide, and in all cases, it was used as an instrument of punishment. This Arabic word could have been brought to England by immigrants. That would make sense, because the first uses of the word seem to have been in the lower classes of London.

As to why “kibosh” rose from being just another slang term, to a phrase we still use today, is suggested by three scholars who recently published an entire book on the word “kibosh.”

The authors relate how in 1834, a Cockney chap was brought into court for violating the 1834 Chimney Sweeps Act, a law intended to stop young children from being put into service as chimney sweeps. According to the book, the fellow had an outburst after the trial in which he complained about the British Whig party and used the expression “to put the kibosh on,” speaking the whole time in an “unmistakable Cockney accent.”

His words were reprinted in newspapers all over England, and soon all types of politicians were talking about “putting the kibosh on the Whigs.” (2,3)

The word has continued to be popular up through today. In fact, opens in a new windowa search of Google Ngrams, which shows how frequently words are used in books, shows “kibosh” being used regularly since the mid-1800s—and spiking in use since 1980.

In short, recent scholars have “put the kibosh” on older theories of where this word came from. Our best guess today is that it’s related to “qurbāsh,” an Arabic word for “whip.”

This post looks at idioms and phrasal verbs in the area of expressing emotions openly or suppressing them within.

Starting with idioms that convey something about showing feelings, if you make no secret of your feelings on a particular subject, you do not try to hide them: He makes no secret of his contempt for the former Prime Minister.

If you pour your heart out, you talk to someone emotionally, for a long time, telling them all about how you feel: She poured her heart out about how difficult life was at home.

To let off steam is to express strong feelings that you have been controlling for a while: I’d had the most frustrating time in the meeting and needed to let off steam.

Someone who wears their heart on their sleeve habitually makes their feelings obvious, making no attempt to hide them: You know what Tom is like – he wears his heart on his sleeve.

And what about idioms for not showing emotions? When someone is determined not to appear upset or disappointed, even though they feel it, we say they put on a brave face, or put a brave face on it: She seemed fairly cheerful but I suspect she was putting on a brave face. / I had to put a brave face on it for the kids.

If you get a grip (on yourself), you try hard to control your emotions and behave calmly, especially when you are very angry or sad: Come on, get a grip! / I was furious, but I had a meeting to attend so I had to get a grip on myself.

Moving on to phrasal verbs in this area, there are a few that convey the idea of trying not to show feelings of sadness or anger, for example hold in: She’d been unhappy for a long time, but holding it in for the kids’ sake.

If someone fights back or holds back tears, they try hard not to cry: He fought back tears as he walked behind his father’s coffin. 

Someone who bottles up feelings such as anger and sadness, stops themselves from showing them to other people for a long time: He never dealt with the grief – just bottled it up for years.

Meanwhile, if someone’s face or manner gives them away, it shows how they really feel, even though they are trying to hide it: She pretends she’s not interested in him, but her interest when his name is mentioned gives her away. / His eyes gave nothing away.

When was the last time you ‘let off steam’? Perhaps you’d like to say in the comments below.

This post looks at idioms and phrasal verbs in the area of expressing emotions openly or suppressing them within.

Starting with idioms that convey something about showing feelings, if you make no secret of your feelings on a particular subject, you do not try to hide them: He makes no secret of his contempt for the former Prime Minister.

If you pour your heart out, you talk to someone emotionally, for a long time, telling them all about how you feel: She poured her heart out about how difficult life was at home.

To let off steam is to express strong feelings that you have been controlling for a while: I’d had the most frustrating time in the meeting and needed to let off steam.

Someone who wears their heart on their sleeve habitually makes their feelings obvious, making no attempt to hide them: You know what Tom is like – he wears his heart on his sleeve.

And what about idioms for not showing emotions? When someone is determined not to appear upset or disappointed, even though they feel it, we say they put on a brave face, or put a brave face on it: She seemed fairly cheerful but I suspect she was putting on a brave face. / I had to put a brave face on it for the kids.

If you get a grip (on yourself), you try hard to control your emotions and behave calmly, especially when you are very angry or sad: Come on, get a grip! / I was furious, but I had a meeting to attend so I had to get a grip on myself.

Moving on to phrasal verbs in this area, there are a few that convey the idea of trying not to show feelings of sadness or anger, for example hold in: She’d been unhappy for a long time, but holding it in for the kids’ sake.

If someone fights back or holds back tears, they try hard not to cry: He fought back tears as he walked behind his father’s coffin. 

Someone who bottles up feelings such as anger and sadness, stops themselves from showing them to other people for a long time: He never dealt with the grief – just bottled it up for years.

Meanwhile, if someone’s face or manner gives them away, it shows how they really feel, even though they are trying to hide it: She pretends she’s not interested in him, but her interest when his name is mentioned gives her away. / His eyes gave nothing away.

When was the last time you ‘let off steam’? Perhaps you’d like to say in the comments below.

As the much-anticipated Oppenheimer movie continues to draw people to the theater by the thousands, it’s a great moment to explore the real-life events and scientific achievements that shaped its gripping narrative. This article by the World War II Museum of New Orleans goes back to the first-ever detonation of a nuclear device.

While most people are familiar with the names of “Little Boy” and “Fat Man” as the atomic weapons used over Japan, what they may not be familiar with was how different the respective technologies of each bomb were and why this difference mattered. 

The Trinity atomic explosion in New Mexico on July 16, 1945, was one of humanity’s most significant scientific achievements. The accession of atomic power in the form of fission is a testament to human ingenuity, technical acumen, and intellectual prowess. At the time, production of such a capability could only be accomplished by the United States. Delivered by Boeing B-29 Superfortress bombers on August 6 and 9, 1945, use of atomic weapons was a symbolic crescendo at the end of the US Army Air Forces’ strategic bombing campaign. To some, these atomic events were seen as retributive justice for the 1941 attack on Pearl Harbor a few years earlier. The atomic bombings of Hiroshima and Nagasaki, combined with other events, helped convince Emperor Hirohito that the Japanese people would soon have to “endure the unendurable and suffer what is insufferable.” 

Such technology was at the very cutting edge of scientific endeavor. But before these atomic attacks occurred, the weapon designs had to be tested. The narrative of the Trinity test near Alamogordo, New Mexico, is often misinterpreted in its importance. Many of the texts and descriptions addressing the end of the Pacific war read as if the New Mexico test was the culminating event for the Manhattan Project, proving atomic weapons were feasible. While that is not necessarily inaccurate, therein lies the misperception. While most people are familiar with the names of “Little Boy” and “Fat Man” as the atomic weapons used over Japan, they may not know how different the respective technologies of each bomb were and why this difference mattered. Little Boy used what was referred to as the “gun method” for creating a fissionable event, while Fat Man used the “implosion method.” While both weapons yielded roughly the same amount of explosive power, what often gets overlooked is that the difference between the two methods had huge implications regarding Pacific war planning. 

The need to drop multiple bombs was determined as early as 1944 by the Military Policy Committee comprised of Army, Navy, and civilian personnel. This organization served not only as an advisory board for Secretary of War Henry Stimson, but also helped bridge the gap between the military and the civilian scientists involved in the Manhattan Project. The multiple weapons approach was initially proposed by Navy representative Rear Admiral William Pursell, who suggested that the use of two or more weapons would be required. The first one would demonstrate the power of the bomb, serving as a warning.  A second bomb would then let the enemy know that the United States had more of these weapons available and that an atomic event was not a singular capability. With multiple strikes, the Japanese would receive a “one-two punch,” causing more angst within the Chrysanthemum Court. Using this approach, the United States needed not just one bomb but a “stockpile” of atomic weapons. With the technology still only speculative, requiring the nation to have multiple atomic weapons available was a tall order.  

The “Trinity” bomb located atop the test tower in the New Mexico Desert. Simply referred to as “the Gadget,” it was a test of the implosion design using plutonium-239. (US Government photo)

Little Boy used a uranium-235 (U-235) slug that traveled down a converted artillery tube, striking a larger sphere of the same substance. Upon contact, an internal initiator released free neutrons simultaneously, creating a critical event resulting in an explosion. While a simple design, one of the problems scientists faced was finding enough U-235. Uranium is a rare earth element that exists largely in a natural state of U-238. Only about 0.7 percent of natural uranium is in the form of U-235 and was available solely in micro quantities. As a result, manmade U-235 had to be extracted from tons of available U-238. Separating the two isotopes was a slow and laborious process done largely with over 1,000 Y-12 “Calutrons” at Oak Ridge, Tennessee. Even with this massive effort, the amount of U-235 produced was barely sufficient for technicians working at the Los Alamos Scientific Lab (LASL) in northern New Mexico. While physicists needed U-235 for their own lab experiments, the uranium-based bomb used up to 140 pounds of the isotope (85 for the target and 55 for the projectile), of which only about 20 pounds became fissionable. As a result, the gun-type bomb was very inefficient with its use of a rare element that was already difficult to produce. 

The need for multiple weapons required even more U-238 and the transformation of it into U-235. With the slow refining process of the isotope, producing the speculated amount needed for another bomb could take as long as six months. This would hardly allow for the “one-two punch” specified by the Military Policy Committee. While some advocated for a demonstration at a barren location to warn the Japanese of the new weapon, the suggestion was rejected for several reasons. First, given the speculative nature of the new technology, if it failed it would be a major embarrassment. Second, if successful, the Japanese may still reject the event as a kind of scientific trick. Third, and more importantly, if successful, the United States had now shot its bolt regarding available U-235.

However, another method for creating a fissionable event was also possible. The basis for this second method was through use of another isotope, plutonium-239 (Pu-239). Physicists determined that Pu-239 was slightly more prone to fission than U-235, which also made it an attractive source for ignition. A largely manmade element that is extremely rare naturally, Pu-239 could be created by bombarding U-238 with neutrons or through a chemical treatment process. Using either of these processes, scientists could more readily produce Pu-239 than they could U-235. In addition to the relative ease of isotope production, significantly less Pu-239 (approximately 13 pounds) was needed for a possible fissionable event. While actual amounts of the fissionable materials required were still speculative, the apparent smaller amount of Pu-239 needed was a boon. Furthermore, given its relative ease of production compared to U-235, developing a plutonium-based weapon was even more attractive. 

Pu-239 could not be made fissionable in the same manner, though, as U-235. Fission for the plutonium-based bomb required the implosion method. Instead of sending a slug of the material into a target, a plutonium sphere could be made super critical if it was compressed equally from all directions. To compress the plutonium sphere, it was surrounded by a complex array of explosive Baratol with accompanying lenses that focused the blast inward. The Baratol was set off by 32 separate detonators that all had to fire simultaneously with a polonium/beryllium initiator providing free electrons. If all the detonators and the initiator fired as planned, the compressed plutonium sphere would in turn go “super critical.” If the initiators did not fire at the same time, an asymmetric force levied on the plutonium core would only yield a large conventional explosion and fail to create a fissionable event.  

Los Alamos head J. Robert Oppenheimer “froze” the design of the uranium-based bomb in February 1945, but further design for the plutonium device continued into the spring and summer. When Oppenheimer “froze” the general design of the plutonium weapon in March, additional refinement of the Fat Man design still took up much of the time for the personnel working at the LASL. However, implosion asymmetry issues were successfully solved by April. While both bombs were indeed science experiments, the physicists and technicians determined that a full test of the gun-type bomb was not required. Field experiments done in late 1944 had already determined the viability of the design. Not only had then been able to verify the potential results in the lab and with smaller explosions, but they could scarcely afford to expend what U-235 they had been able to extract. 

Given these considerations, the Trinity event validated only the implosion design. This initial implosion device was referred to by LASL personnel simply as “the gadget.” This test of the gadget was important was for several reasons. First, it would determine where a fissionable event with Pu-239 was workable given the design challenges. Second, if successful and given the relative ease of production of the isotope, America could now produce multiple atomic weapons creating a stockpile of sorts. Third, and perhaps most importantly, the United States would quickly have multiple bombs to provide the “one-two punch” mandated by the Military Policy Committee. The successful Trinity explosion meant that not only did the United States have two viable weapons and designs, but it could also easily make more bombs should that be required. 

In the days following the Trinity explosion, President Harry S. Truman attended the Potsdam Conference on the outskirts of Berlin. Knowing the results of the New Mexico tests, Truman met with other Allied leaders and drafted the “Potsdam Declaration,” specifically calling on the Japanese to surrender or face “prompt and utter destruction.” While the Trinity test validated the use of plutonium and the concept of implosion, it gave, more importantly, the United States a notional stockpile. With the possibility of multiple atomic weapons, the United States could now execute a “rain of ruin” on the Japanese homeland that was indeed unparalleled.  

As the much-anticipated Oppenheimer movie continues to draw people to the theater by the thousands, it’s a great moment to explore the real-life events and scientific achievements that shaped its gripping narrative. This article by the World War II Museum of New Orleans goes back to the first-ever detonation of a nuclear device.

While most people are familiar with the names of “Little Boy” and “Fat Man” as the atomic weapons used over Japan, what they may not be familiar with was how different the respective technologies of each bomb were and why this difference mattered. 

The Trinity atomic explosion in New Mexico on July 16, 1945, was one of humanity’s most significant scientific achievements. The accession of atomic power in the form of fission is a testament to human ingenuity, technical acumen, and intellectual prowess. At the time, production of such a capability could only be accomplished by the United States. Delivered by Boeing B-29 Superfortress bombers on August 6 and 9, 1945, use of atomic weapons was a symbolic crescendo at the end of the US Army Air Forces’ strategic bombing campaign. To some, these atomic events were seen as retributive justice for the 1941 attack on Pearl Harbor a few years earlier. The atomic bombings of Hiroshima and Nagasaki, combined with other events, helped convince Emperor Hirohito that the Japanese people would soon have to “endure the unendurable and suffer what is insufferable.” 

Such technology was at the very cutting edge of scientific endeavor. But before these atomic attacks occurred, the weapon designs had to be tested. The narrative of the Trinity test near Alamogordo, New Mexico, is often misinterpreted in its importance. Many of the texts and descriptions addressing the end of the Pacific war read as if the New Mexico test was the culminating event for the Manhattan Project, proving atomic weapons were feasible. While that is not necessarily inaccurate, therein lies the misperception. While most people are familiar with the names of “Little Boy” and “Fat Man” as the atomic weapons used over Japan, they may not know how different the respective technologies of each bomb were and why this difference mattered. Little Boy used what was referred to as the “gun method” for creating a fissionable event, while Fat Man used the “implosion method.” While both weapons yielded roughly the same amount of explosive power, what often gets overlooked is that the difference between the two methods had huge implications regarding Pacific war planning. 

The need to drop multiple bombs was determined as early as 1944 by the Military Policy Committee comprised of Army, Navy, and civilian personnel. This organization served not only as an advisory board for Secretary of War Henry Stimson, but also helped bridge the gap between the military and the civilian scientists involved in the Manhattan Project. The multiple weapons approach was initially proposed by Navy representative Rear Admiral William Pursell, who suggested that the use of two or more weapons would be required. The first one would demonstrate the power of the bomb, serving as a warning.  A second bomb would then let the enemy know that the United States had more of these weapons available and that an atomic event was not a singular capability. With multiple strikes, the Japanese would receive a “one-two punch,” causing more angst within the Chrysanthemum Court. Using this approach, the United States needed not just one bomb but a “stockpile” of atomic weapons. With the technology still only speculative, requiring the nation to have multiple atomic weapons available was a tall order.  

The “Trinity” bomb located atop the test tower in the New Mexico Desert. Simply referred to as “the Gadget,” it was a test of the implosion design using plutonium-239. (US Government photo)

Little Boy used a uranium-235 (U-235) slug that traveled down a converted artillery tube, striking a larger sphere of the same substance. Upon contact, an internal initiator released free neutrons simultaneously, creating a critical event resulting in an explosion. While a simple design, one of the problems scientists faced was finding enough U-235. Uranium is a rare earth element that exists largely in a natural state of U-238. Only about 0.7 percent of natural uranium is in the form of U-235 and was available solely in micro quantities. As a result, manmade U-235 had to be extracted from tons of available U-238. Separating the two isotopes was a slow and laborious process done largely with over 1,000 Y-12 “Calutrons” at Oak Ridge, Tennessee. Even with this massive effort, the amount of U-235 produced was barely sufficient for technicians working at the Los Alamos Scientific Lab (LASL) in northern New Mexico. While physicists needed U-235 for their own lab experiments, the uranium-based bomb used up to 140 pounds of the isotope (85 for the target and 55 for the projectile), of which only about 20 pounds became fissionable. As a result, the gun-type bomb was very inefficient with its use of a rare element that was already difficult to produce. 

The need for multiple weapons required even more U-238 and the transformation of it into U-235. With the slow refining process of the isotope, producing the speculated amount needed for another bomb could take as long as six months. This would hardly allow for the “one-two punch” specified by the Military Policy Committee. While some advocated for a demonstration at a barren location to warn the Japanese of the new weapon, the suggestion was rejected for several reasons. First, given the speculative nature of the new technology, if it failed it would be a major embarrassment. Second, if successful, the Japanese may still reject the event as a kind of scientific trick. Third, and more importantly, if successful, the United States had now shot its bolt regarding available U-235.

However, another method for creating a fissionable event was also possible. The basis for this second method was through use of another isotope, plutonium-239 (Pu-239). Physicists determined that Pu-239 was slightly more prone to fission than U-235, which also made it an attractive source for ignition. A largely manmade element that is extremely rare naturally, Pu-239 could be created by bombarding U-238 with neutrons or through a chemical treatment process. Using either of these processes, scientists could more readily produce Pu-239 than they could U-235. In addition to the relative ease of isotope production, significantly less Pu-239 (approximately 13 pounds) was needed for a possible fissionable event. While actual amounts of the fissionable materials required were still speculative, the apparent smaller amount of Pu-239 needed was a boon. Furthermore, given its relative ease of production compared to U-235, developing a plutonium-based weapon was even more attractive. 

Pu-239 could not be made fissionable in the same manner, though, as U-235. Fission for the plutonium-based bomb required the implosion method. Instead of sending a slug of the material into a target, a plutonium sphere could be made super critical if it was compressed equally from all directions. To compress the plutonium sphere, it was surrounded by a complex array of explosive Baratol with accompanying lenses that focused the blast inward. The Baratol was set off by 32 separate detonators that all had to fire simultaneously with a polonium/beryllium initiator providing free electrons. If all the detonators and the initiator fired as planned, the compressed plutonium sphere would in turn go “super critical.” If the initiators did not fire at the same time, an asymmetric force levied on the plutonium core would only yield a large conventional explosion and fail to create a fissionable event.  

Los Alamos head J. Robert Oppenheimer “froze” the design of the uranium-based bomb in February 1945, but further design for the plutonium device continued into the spring and summer. When Oppenheimer “froze” the general design of the plutonium weapon in March, additional refinement of the Fat Man design still took up much of the time for the personnel working at the LASL. However, implosion asymmetry issues were successfully solved by April. While both bombs were indeed science experiments, the physicists and technicians determined that a full test of the gun-type bomb was not required. Field experiments done in late 1944 had already determined the viability of the design. Not only had then been able to verify the potential results in the lab and with smaller explosions, but they could scarcely afford to expend what U-235 they had been able to extract. 

Given these considerations, the Trinity event validated only the implosion design. This initial implosion device was referred to by LASL personnel simply as “the gadget.” This test of the gadget was important was for several reasons. First, it would determine where a fissionable event with Pu-239 was workable given the design challenges. Second, if successful and given the relative ease of production of the isotope, America could now produce multiple atomic weapons creating a stockpile of sorts. Third, and perhaps most importantly, the United States would quickly have multiple bombs to provide the “one-two punch” mandated by the Military Policy Committee. The successful Trinity explosion meant that not only did the United States have two viable weapons and designs, but it could also easily make more bombs should that be required. 

In the days following the Trinity explosion, President Harry S. Truman attended the Potsdam Conference on the outskirts of Berlin. Knowing the results of the New Mexico tests, Truman met with other Allied leaders and drafted the “Potsdam Declaration,” specifically calling on the Japanese to surrender or face “prompt and utter destruction.” While the Trinity test validated the use of plutonium and the concept of implosion, it gave, more importantly, the United States a notional stockpile. With the possibility of multiple atomic weapons, the United States could now execute a “rain of ruin” on the Japanese homeland that was indeed unparalleled.