[ass] n [ME, fr. OE assa, prob. fr. OIr asan, fr. L asinus] (bef. 12c) 1: any of several hardy gregarious African or Asian perissodactyl mammals (genus Equus) smaller than the horse and having long ears; esp: an African mammal (E. asinus) that is the ancestor of the donkey
2: a stupid, obstinate, or perverse person--often compounded with a preceding adjective "don't be a smart-ass"--often considered vulgar
[2]ass or arse n [ME ars, ers, fr. OE aers, ears; akin to OHG & ON ars buttocks, Gk orrhos buttocks, oura tail] (bef. 12c) 1 a: buttocks--often used in emphatic reference to a specific person "get your ~ over here" "saved my ~"--often considered vulgar b: anus--often considered vulgar
2: sexual intercourse--usu. considered vulgar [3]ass adv [
[2]ass] (1955)--used as a postpositive intensive esp. with words of derogatory implication "fancy-ass"--often considered vulgar