onager

‖n.; pl. L. Onagri E. Onagers [ L. onager, onagrus, Gr. &unr_;. ] 1. (Rom. Antiq.) A military engine acting like a sling, which threw stones from a bag or wooden bucket, and was operated by machinery. Fairholt. [ 1913 Webster ]

2. (Zool.) A wild ass of central Asia, especially the koulan (Equus hemionus syn. Equus hemippus syn. Equus onager, formely Asinus onager). [ 1913 Webster +PJC ]