D defs.my
Entry 2 senses Webster, 1913

Jackass

/jăk'-ăsˌ/ · Jack·ass · IPA /ˈd͡ʒækæs/
01 n. The male ass; a donkey.
  1. 1.
    The male ass; a donkey.
  2. 2.
    A conceited dolt; a perverse blockhead; -- disparaging and offensive.
Phrases & compounds
Jackass bark — a three-masted vessel, with only the foremast square-rigged; a barkentine.
Jackass deer — the koba.
Jackass hare — See Jack rabbit, under 2d Jack, n.
Jackass penguin — any species of penguin of the genus Spheniscus, of which several are known. One species (Spheniscus demersus) inhabits the islands near the Cape of Good Hope; another (Spheniscus Magellanicus) is found at the Falkland Islands. They make a noise like the braying of an ass; -- hence the name.
Laughing jackass — See under Laughing.