βρυγμός
From LSJ
Γύμναζε παῖδας· ἄνδρας οὐ γὰρ γυμνάσεις → Exerce pueros: non exercebis virum → Mit Kindern übe, denn mit Männern ist's zu spät
English (LSJ)
ὁ,
A biting, ib.716 (pl., v.l. βρυχμός); gobbling, Eup.347; chattering, shivering, Hp.Vict.3.84, Steril.214, Euryphon ap.Gal.17(1).888; β. ὀδόντων gnashing of teeth, Ev.Matt.8.12, al. II roaring of a lion, LXX Pr.19.12.