v. & n.
v. 1 tr. a crush noisily with the teeth. b grind (gravel, dry snow, etc.) under foot, wheels, etc. 2 intr. (often foll. by up, through) make a crunching sound in walking, moving, etc.
n. 1 crunching; a crunching sound. 2 colloq. a decisive event or moment.
[ earlier cra(u)nch, assim. to munch ]