[on.a.ger] n [ME, wild ass, fr. L, fr. Gk onagros, fr. onos ass + agros field--more at acre] (14c) 1: an Asian wild ass (Equus hemionus onager syn. E. onager) that usu. has a broad dorsal stripe and is related to the kiang
2. [LL, fr. L]: a heavy catapult used in ancient and medieval times