Some people have claimed that the word corduroy comes from the French phrase corde du roi, which means "cloth of the king". Interesting hypothesis, but nobody is recorded as ever having said that in French. So, forget that. The most likely theory is that corduroy comes from the English word cord and duroy, an obsolete term for ab obsolete type of fabric. Duroy is so obscure and antiquated that, while it is attested, there is no discernible etymology. Meanwhile, cord has a very widely accepted origin. It comes from French corde (yes, that corde; the alleged "cloth" meaning is very rare), with the same meaning, from Latin chorda, a word which literally meant "cat-gut" as many cords were constructed out of animal intestines. Through Greek khorde, this comes from Proto-Indo-European ghere, meaning "intestine".
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.