Dictionary

To crush something, especially food, with a noisy crackling sound.

Example: When I came home, Susan was watching TV with her feet up on the couch, crunching a piece of celery.

To be crushed with a noisy crackling sound.

Example: Beetles crunched beneath the men's heavy boots as they worked.

To calculate or otherwise process (e.g. to crunch numbers: to perform mathematical calculations). Presumably from the sound made by mechanical calculators.

Example: That metadata makes it much easier for the search engine to crunch the data for queries.

To grind or press with violence and noise.

A crunch noise.