1. The word “Bupkis,” common slang for “nothing,” comes from the Yiddish phrase meaning “having about as much worth as goat turds.” – source
2. The phrase youre toast is thought to have been coined by Bill Murray when he ad libbed the phrase in a scene in the 1984 film Ghost Busters. – source
3. The word “Goodbye” is actually a contraction of the phrase “God Be With You”. I had no idea. – source
4. The use of the phrase “Checkmate” is derived from a mispronunciation of the original Persian, “Shh mt!”, which means the king is helpless. – source
5. We say “pardon my French” after swearing because in the 19th century, English-speaking people would drop French phrases into conversation to display class, apologizing because many of their listeners wouldn’t know the language. Then people hid swear words under the pretense of them being French. – source
6. Modern English speakers use the phrase crocodile tears to describe people who shed false tears, or pretend to cry to gain sympathy. But the saying actually derives from a medieval belief that crocodiles would shed tears of sadness while they killed and consumed their prey. – source
7. The phrase “to turn a blind eye” comes from British Vice Admiral Nelson, who was blind in one eye; in one battle, when he was signaled to stop attacking a fleet of Danish ships, he held up a telescope to his blind eye, saying “I really do not see the signal,” and attacked anyway. – source
8. The phrase “Cut to the chase” comes from silent movies which often ended with a chase scene. When the film had boring, or too much dialogue executives would say this to the directors. – source
9. When horses get old, their gum line recedes, making their teeth appear longer. The phrase dont look a gift horse in the mouth is derived from the practice of actually checking inside the mouth of horses to check the age of the horse you were receiving or trading for. – source
10. The phrase break a leg allegedly originates from theatrical superstitions. In theater, it is considered bad luck to say something like, good luck or have a great performance – the thought is that saying it outloud would make the opposite occur, like a jinx. So, to combat this, actors would instead wish something horrible on the person – break a leg – so that the opposite of that would occur and everyone would have a great performance. – source
11. An alternative explanation for the origin of break a leg also states that “Break a leg” originates in the theater, but that it has nothing to do with superstition. The curtains along the side of the stage are called “legs,” and when a crowd loved a performance and cheered and called for curtain call after curtain call, the legs would often break. That is the origin of that phrase.
12. Carnivals used to give out cigars as prizes, so when somebody came close to winning a carnival game, they would say, close but no cigar which now refers to coming close to your goal but falling short. – source
13. The phrase mind your Ps and Qs which means mind your manners, is said to originate from 17th century pubs, where Pints and Quarts were served. The bartender would tell drunk, unruly customers to mind their Ps and Qs, which now just refers to behavior in general, not just drunk behavior. – source
14. An alternative explanation is that “Mind your P’s and Q’s” originates from the days of the printing press. Lead and wooden letters used in letterpress are backwards, so lowercase p’s and q’s are easily mistaken for one another. Pressmen had to pay close attention or risk major typos. – source
15. The phrase bite the bullet, which refers to accepting hard situations or circumstances, is said to originate from wartime medics who often had to perform surgery without anaesthetic – soldiers were told to bite down on a bullet to distract them from the extreme pain. – source
BONUS: Constantinople became known as Istanbul because people started referring to it as “The City” and the Greek phrase for “In The City” is pronounced “Is Tin Poli.” Over time, this became Istanbul. – source