infrēnis, e, and infrēnus, a, um (infraen-), adj. 2. in - frenum, without a bridle, unbridled (poet. and post-class.). Lit.: infrenis equus, Verg. A. 10, 750: Numidae infreni, on unbridled horses, id. ib. 4, 41.

— Trop., untamed, unchecked: infreno volitare cursu, Col. poet. 10, 215: lingua infrenis, Gell. 1, 15, 17: infrenus manat de vulnere sanguis, Ser. Samm. 43, 804.