Cahoots
wiktionary
From earlier cahoot. This word was used in popular English literature in the early nineteenth century. It comes perhaps from French cahute(“hut”), from Middle French quahute, from Old French *cahute, chahute, possibly as a blend of cabane(“cabin”) and/or caverne(“cavern”) + Old French hute(“hut”); or alternatively from Old French ca-(pejorative prefix) + hute(“hut”). Also possibly considered to be from French cohorte, or a slang form of English cohort in the meaning "accomplice."
etymonline
cahoots (n.)
"company, partnership," 1829, Southern and Western American English, of unknown origin; said [OED] to be perhaps from French cahute "cabin, hut" (12c.), but U.S. sources [Bartlett] credit it to French cohorte (see cohort), which is said to have had a sense of "companions, confederates."
