reduncus
From LSJ
rĕd-uncus: a, um, adj.,
I 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.