What is the meaning of Onager?

The Asiatic wild ass or hemione (Equus hemionus), an animal of the horse family native to Asia; specifically, the Persian onager, Persian wild ass, or Persian zebra (Equus hemionus onager).

A military engine acting like a sling which threw stones from a bag or wooden bucket powered by the torsion from a bundle of ropes or sinews operated by machinery; a torsion catapult.

onager, Asiatic wild ass, Equus hemionus

onager (Roman torsion catapult)

wild ass; onager

onager (type of military engine)

(clarification of this definition is needed.)onager

onager (the Asiatic wild ass or hemione (Equus hemionus), an animal of the horse family native to Asia; specifically, the Persian onager, Persian wild ass, or Persian zebra (Equus hemionus onager))

onager (a military engine acting like a sling which threw stones from a bag or wooden bucket powered by the torsion from a bundle of ropes or sinews operated by machinery; a torsion catapult)

Source: wiktionary.org