v. phr. , informal 1. Decide what you want to do and stop wasting time; either act now or give someone else a chance or turn. Jack couldn't decide whether to go to college or get a job, so his father told him to fish or cut bait. "Buy the kind of ice cream you want or give someone else in line a chance. Fish or cut bait!"
Compare: MAKE UP ONE'S MIND. 2. Either try hard and do your best, or quit. Frank missed football practice so often that the coach told him to fish or cut bait.