From Longman Dictionary of Contemporary Englishassass /æs/ noun [countable] 1 STUPID/NOT INTELLIGENT not polite a stupid annoying person SYN foolHe’s a pompous ass.make an ass of yourself (=do something stupid or embarrassing)2 HBHRUDE/IMPOLITE American English not polite the part of your body that you sit on3 HBA old use a donkey → arse1, → get your butt/ass in gear at gear1(8), → haul ass at haul1(5), → kick ass at kick1(8), → kick somebody’s ass at kick1(7), → kiss somebody’s ass at kiss1(6), → be a pain in the ass at pain1(3), → piece of ass at piece1(24), → smart arse, → work your ass off at work1(30)
Examples from the Corpus
ass• I heard him on TV. He's such an ass.• I fell down on my ass.• She took a great deal of satisfaction in seeing the pompous old ass upset.Origin ass 1. Old English assa, from Latin asinus2. (1800-1900) Changed spelling of arse ((11-21 centuries)), from Old English ærs, ears 