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".
Adam Aleksic, a leading contender for valedictorian of his high school, is a 210-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and probably isn't spying for the Kyrgyz government.
The Etymology Nerd