GNASH, verb transitive nash. To strike the teeth together, as in anger or pain; as, to gnash the teeth in rage.
GNASH, verb intransitive nash. To grind the teeth.
He shall gnash with his teeth and melt away. Psalms 112:10.
1. To rage even to collision with the teeth; to growl.
They gnashed on me with their teeth. Psalms 35:16.