in-frendeo, ēre, and in-frendo, ere, v. n., to gnash the teeth (poet. and postclass.): dentibus infrendens gemitu, Verg. A. 3, 664: ac simul infrendens, Stat. Th. 5, 663: infrendite, inspumate, Tert. Apol. 12.

— To gnash the teeth at, threaten furiously; with dat.: aliis infrendentem, Stat. Th. 8, 580.