reduncus

rĕd-uncus, a, um, adj.,

curved or bent backwards (very rare; syn.: recurvus, repandus): jamque aliis adunca, aliis redunca (cornua dedit), Plin. 11, 37, 45, § 125.— Poet., in gen., curved , bent : pennis rostroque redunco, Ov. M. 12, 562: ora redunca, id. ib. 11, 342.