WordNet sense 1 (press or grind with a crunching noise):

grind, cranch, craunch

WordNet sense 2 (chew noisily):

munch

WordNet sense 3 (make crunching noises):

crackle, scranch, scraunch

WordNet sense 4 (the act of crushing):

crush, compaction

WordNet sense 5 (reduce to small pieces or particles by pounding or abrading):

bray, comminute, mash