The Collaborative International Dictionary
Jackass \Jack"ass`\, n. [2d jack + ass.]
- The male ass; a donkey. 
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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 (Zo["o]l.), the koba. Jackass hare, Jackass rabbit (Zo["o]l.). See Jack rabbit, under 2d Jack, n. Jackass penguin (Zo["o]l.), 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. (Zo["o]l.) See under Laughing.