Cahoot is a word meaning "partnership" that curiously almost never shows up in its singular form. We only ever see the term as part of the phrase in cahoots (which has more negative, conspiratorial connotations), which traces back to the mid-eighteenth century. Cahoot was around for a little bit before that, with its first attestation in an 1829 grammar book, but it eventually faded as the expression stayed prominent. Linguists aren't quite sure where that comes from, because it seems like it popped out of nowhere in the American south, but the main (tenuous) theory right now is that cahoot came from the French word cahute, meaning "hut" (maybe partnerships were formed. That's from Dutch kajuit, which is from Middle Dutch kayhute, which also has an unknown origin.
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.