I'm surprised I never looked this up before, but the word caucus has some fascinating potential origins. The American Heritage Dictionary suggests that it might come from a Latin word meaning "drinking cup", but the Oxford English Dictionary disparages this theory - it would be inconsistent with meaning and early usages. The most likely explanation, especially since it first showed up in North American newspapers in the mid-eighteenth century, is that it was borrowed from a Native American language. A suitable candidate would be caucauasu, a noun in a Virginian dialect of Algonquin meaning "counselor" or "adviser". The definition would have shifted to denote informal policy advising sessions by political elites, and eventually to the voting process. I should note, however, that this is still disputed, and there are some unexplained possible inconsistencies with the names of ships and social clubs.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.