Lewis & Short

vespertīnus, a, um, adj. [vesper].

  1. I. Of or belonging to evening or even-tide, evening-: tempora (opp. matutina), Cic. N. D. 2, 20, 52: litterae, received in the evening (opp. antemeridianae), id. Att. 13, 23, 1: senatusconsulta, made or passed in the evening, id. Phil. 3, 10, 24: acies, a seeing dimly in the evening, Plin. 8, 50, 76, § 203: cantus, of the cock, id. 10, 21, 24, § 49: lucubratio, id. 18, 26, 63, § 233: ros, evening dew, Pall. Nov. 13, 4 et saep.
    Adverb.: si vespertinus subito te oppresserit hospes, i. e. in the evening, Hor. S. 2, 4, 17; id. Epod. 16, 51; id. S. 1, 6, 113; Prud. Psych. 376.
    Absol.: vespertino rursus pascunt, at even-tide, Varr. R. R. 2, 2, 11: matutinis vespertinisque, in the morning and evening hours, Plin. 30, 10, 24, § 84.
  2. II. Of or belonging to the west, western: regio, Hor. S. 1, 4, 30: caeli regio, Vitr. 4, 5, 1: populus, Prud. Psych. 376.