definition of
go bad

[1] #1 go bad v. 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". wn

[2] #2 go bad v. become unfit for consumption or use; "the meat must be eaten before it spoils". wn