Lewis & Short

infrēnis, e, and infrēnus, a, um (infraen-), adj. [2. in-frenum], without a bridle, unbridled (poet. and post-class.).

  1. I. Lit.: infrenis equus, Verg. A. 10, 750: Numidae infreni, on unbridled horses, id. ib. 4, 41.
  2. II. Trop., untamed, unchecked: infreno volitare cursu, Col. poët. 10, 215: lingua infrenis, Gell. 1, 15, 17: infrenus manat de vulnere sanguis, Ser. Samm. 43, 804.