Jack·ass n.
 1. The male ass; a donkey.
 2. A conceited dolt; a perverse blockhead; -- disparaging and offensive.
 Jackass bark Naut., a three-masted vessel, with only the foremast square-rigged; a barkentine.
 Jackass deer Zool., the koba.
 Jackass hare, Jackass rabbit Zool.. See Jack rabbit, under 2d Jack, n.
 Jackass penguin Zool., 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. Zool. See under Laughing.
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