Green’s Dictionary of Slang

(US campus) to be disgusting, unappealing, second-rate.

1983		A. Naiman Computer Dict. 312: This new editor really chomps [HDAS].
1990–2001		E. Raymond Jargon File 4.3.1 🌐 chomp vi. To lose; specifically, to chew on something of which more was bitten off than one can. Probably related to gnashing of teeth.