1560s, from Late Latin, from Greek hysteron-proteron, literally "the latter (put as) the former." A cart-before-the-horse figure of speech, in which what should come last is put first. From hysteron, neuter of hysteros "latter, second, after" (from PIE *ud-tero-, from root *ud- "up, out;" see out (adv.)) + proteron, neuter of proteros "before, former," from PIE *pro-, from root *per- (1) "forward," hence "in front of, before, first."