IDIOM ►

pinch hit for someone

Meaning 1
to substitute for someone
Sentence 1
We need a run. John, will you pinch hit for the pitcher?
Meaning 2
to substitute for someone
Sentence 2
Mary, will you please pinchhit for John on this account, while he is on vacation?

Derivation

A batter who is not in the lineup for a particular date can pinch hit for another batter.