{ } a. [ From NL. Onagra an old scientific name of the evening primrose (Œnothera), fr. Gr. 'ona`gra a kind of plant; of uncertain origin. ] (Bot.) Pertaining to, or resembling, a natural order of plants (Onagraceae or Onagrarieae), which includes the fuchsia, the willow-herb (Epilobium), and the evening primrose (Œnothera). [ 1913 Webster ]