Entry 2 senses · 2 variants Webster, 1913 Onagra · O·nag·ra · IPA prop. n. n. 01 prop. n. Same as Oenothera, a genus of plants consisting of the evening primrose. 1. Same as Oenothera, a genus of plants consisting of the evening primrose.(Bot.) 02 n. The female of the onager. 1. The female of the onager.