βρυγμὸς [7 verses](noun sg masc nom) "Gnashing" is brugmos, which means "biting," "gobbling," and "chattering."  - (CW) The word translated as "gnashing" which primarily means "biting" but "chattering" works well too.   It doesn't mean "grinding" which is the meaning of gnashing."CW --Confusing Word --  It doesn't mean "grinding" which is the meaning of gnashing."