ˈpinch-hit verb [intransitive + for] American English

1. to do something for someone else because they are suddenly not able to do it

2. to hit for someone else in baseball
—pinch-hitter noun [countable]

[TahlilGaran] Dictionary of Contemporary English ▲

pinch-hit
[American]
to do something for someone because they are suddenly unable to do it.
He was pinch-hitting for one of the regular TV sportscasters, and was a great success.
(often + for)

[TahlilGaran] English Idioms Dictionary ▲

pinch hit
v.
1. To substitute for another player at bat in a baseball game.
Smith was sent in to pinch-hit for Jones.
2. informal To act for a while, or in an emergency, for another person; take someone's place for a while.
I asked him to pinch-hit for me while I was away.
The president of the City Council pinch-hits for the mayor when the mayor is out of town. -

[TahlilGaran] English Idioms Dictionary ▲