jack·ass \ˈjaˌkas, -kaa(ə)s, -kais also -kȧs in New Eng & Brit especially (in Brit at least) in sense 2\noun Etymology:jack (I) + ass 1. a.: a male ass; also: donkey b.Australia: kookaburra 2.: a stupid person : fool, dolt < a conceited jackass > 3.: hawse bag