Merriam-Webster's Collegiate® Dictionary, 11th Edition
CRUNCH
I. verb
Etymology: alteration of craunch
Date: 1706
intransitive verb to chew or press with a crushing noise, to make one's way with a crushing noise, transitive verb to chew, press, or grind with a crunching sound, process , crunchable adjective
II. noun
Date: 1832
an act of crunching, a sound made by crunching, a tight or critical situation: as, a critical point in the buildup of pressure between opposing elements ; showdown , a severe economic squeeze (as on credit), shortage , a conditioning exercise performed from a supine position by raising and lowering the upper torso without reaching a sitting position