Definitions of crunch:

• noun:   the sound of something crunching

  Example: "He heard the crunch of footsteps on the gravel path"

• noun:   a critical situation that arises because of a shortage (as a shortage of time or money or resources)

  Example: "An end-of-the year crunch"

• noun:   the act of crushing
• verb:   make crunching noises

  Example: "His shoes were crunching on the gravel"

• verb:   chew noisily

  Example: "The children crunched the celery sticks"

• verb:   press or grind with a crunching noise
• verb:   reduce to small pieces or particles by pounding or abrading