The first uses of the word shiv (meaning "sharp thing used as a weapon", originally also spelled shive) emerged in New York City underworld slang in 1915 as a variant of the existing word chiv/chive/chieve, which similarly meant "knife" in British Thieves' Cant. That emerged in London prisons at some point in the mid-seventeenth century, and the Oxford English Dictionary doesn't comment on its etymology. However, several other sources suggest that it may derive from a Romani word spelled something like chivomengro and meaning "knife" (this would ultimately trace to the Sanskrit noun churi, still "knife". The word shiv kept a fairly low profile in American English until 1990s, when it skyrocketed in usage due to being popularized by rappers and U.S. prisons.
Hello! I'm Adam Aleksic. This year, I graduated from Harvard University with a degree in Government and Linguistics. There, I co-founded the Harvard Undergraduate Linguistics Society and wrote a thesis on Serbo-Croatian language policy, magna cum laude. In addition to etymology, I also really enjoy philosophy, trivia, vexillology, geography, board games, conlanging, art history, and law.