Green’s Dictionary of Slang

1. a generic term for women.

1976		Eble Campus Sl. Nov. 2: Crunch [...] girls, especially girls responsive to sexual advances.
1996		Eble Sl. and Sociability 44: The meanings associated with many of these pictures of destruction are scattered in subject area — crunch a collective noun for ‘females’.

2. an infatuation.

1974

Eble Campus Sl. Apr. 1: crunch – a minor infatuation with a person; the person with whom one is infatuated.