Onager

·noun A wild ass, especially the koulan.

II. Onager ·noun A military engine acting like a sling, which threw stones from a bag or wooden bucket, and was operated by machinery.

onager
ŏnăger and ŏnā̆grus, i, m., = ὄναγρος, I a wild ass , Varr. R. R. 2, 6, 3; cf. Col. 6, 37, 3; ...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
onager
onager ī, m , ὄναγρος, a wild ass, V. ...

An Elementary Latin Dictionary