Lewis & Short

Fĕrētrĭus, ii, m. [ferio; cf. in the foll., Prop. 4 (5), 10, 45; acc. to Liv. 1, 10, 6, from fero], a surname of Jupiter, the subduer of enemies, and to whom the spolia opima were consequently offered.

  1. I. Prop.: nunc spolia in templo tria condita causa Feretri, Omine quod certo dux ferit ense ducem, Prop. 4 (5), 10, 45; cf. id. ib. 1 sq.; Liv. 1, 10, 6; 1, 33 fin.; 4, 20 sq.; Nep. Att. 20, 3; Flor. 1, 1, 11; Paul. ex Fest. p. 92, 1 Müll. al.
  2. * II. Transf., of Amor: opima apposui senex Amori arma Feretrio, Poët. ap. Ter. Maur. p. 2442 P.