Grist

According to the Old English Dictionary:

(?)

grist

gnashing of teeth, in the cpds. grist-bátian, -bátung, -bite, -bitian, -bitung. [Cf. O. Sax. grist-grimmo gnashing of teeth in rage: O. H. Ger. gris-gramón stridere, fremere dentibus; gris-grimmón stridere; grist-grimmung stridor.] See next word. grist