Lewis & Short

† oestrus, i, m., = οἶστρος.

  1. I. Lit., a gad-fly, horse-fly, breese (pure Lat. asilus): volitans, cui nomen asilo Romanum est, oestrum Graii vertere vocantes, Verg. G. 3, 148: nascuntur in extremis favis apes grandiores, quae ceteras fugant: oestrus vocatur hoc malum, Plin. 11, 16, 16, § 47.
  2. II. Transf., frenzy of a prophet or poet, inspiration, enthusiasm (in post-Aug. poets), Stat. Th. 1, 32; Nemes. Cyneg. 3; Juv. 4, 123; cf.: oestrum furor Graeco vocabulo, Paul. ex Fest. p. 195 Müll.