From WordNet (r) 3.0 (2006) [wn]:
go bad
v 1: stop operating or functioning; "The engine finally went";
"The car died on the road"; "The bus we travelled in broke
down on the way to town"; "The coffee maker broke"; "The
engine failed on the way to town"; "her eyesight went after
the accident" [syn: fail, go bad, give way, die,
give out, conk out, go, break, break down]
2: become unfit for consumption or use; "the meat must be eaten
before it spoils" [syn: spoil, go bad]