1. In baseball or softball, to bat in place of another player. Let Ben pinch-hit—he's a better hitter than Paul, and you really need to knock in some runs here. In a surprise move, the rookie is going to pinch-hit for the veteran batter.

2. By extension, to do something in place or on behalf of someone else. I have a doctor's appointment this afternoon, so I need you to pinch-hit for me on the conference call. I'm afraid I can't make it to the meeting, so my second in command will be there pinch-hitting for me.