raise one's hand

Short definition from Wiktionary

Verb

1. 1
   Used other than figuratively or idiomatically: see raise, hand.
2. 2
   To use the gesture (either literally or figuratively) in order: To volunteer.
3. 3
   To use the gesture (either literally or figuratively) in order: To vote; to indicate agreement or approval.
4. 4
   To use the gesture (either literally or figuratively) in order: To ask a question or make a request.
5. 5
   To assault physically, notionally with the hand or fist.