Illustration of onager
- onager 2
onager
noun
on·a·ger ˈä-ni-jər 
1
: an Asian wild ass (Equus hemionus onager synonym E. onager) that usually has a broad dorsal stripe and is related to the kiang
2
[Late Latin, from Latin] : a heavy catapult used in ancient and medieval times
Example Sentences
Recent Examples on the Web Now, analysis of DNA extracted from the bones buried at Umm el-Marra has revealed the animal was a cross between a donkey, which was domesticated at the time, and the now-extinct Syrian wild ass, sometimes called hemippe or an onager. 
Katie Hunt, CNN, 14 Jan. 2022 Researchers have uncovered thousands of bone fragments at the site, including remains from horses, extinct wild oxen known as aurochs, and donkey relatives called onagers. Maya Wei-haas, National Geographic, 24 July 2019 The two of them once passed two very happy weekends of courtship in attempts to reconstruct an ancient catapult called an onager. Gideon Lewis-kraus, WIRED, 18 June 2018
Katie Hunt, CNN, 14 Jan. 2022 Researchers have uncovered thousands of bone fragments at the site, including remains from horses, extinct wild oxen known as aurochs, and donkey relatives called onagers. Maya Wei-haas, National Geographic, 24 July 2019 The two of them once passed two very happy weekends of courtship in attempts to reconstruct an ancient catapult called an onager. Gideon Lewis-kraus, WIRED, 18 June 2018 Word History
Etymology
Middle English, wild ass, from Latin, from Greek onagros, from onos ass + agros field — more at acre
First Known Use
14th century, in the meaning defined at sense 1