Definitions for "Onager "
A military engine acting like a sling, which threw stones from a bag or wooden bucket, and was operated by machinery.
A wild ass of central Asia, especially the koulan (Equus hemionus syn. Equus hemippus syn. Equus onager, formely Asinus onager).
A wild donkey. Also the name of a Roman war-machine, which hurled stones at the enemy.