To take (preventive) measures; to take steps in advance to avoid problems.
問題が大きくなる前に手を打つ必要がある。
We need to take action before the problem grows.
To come to an agreement (in bargaining or negotiation); to strike a bargain or make arrangements.
価格については両社で手を打って、正式契約に進むことになった。
The two companies agreed on the price and decided to proceed to a formal contract.
早めに手を打てば、無駄なコストを避けられると交渉相手と手を打った。
We struck a deal with the negotiator that taking early measures would avoid unnecessary costs.
To clap one's hands together; to strike with the hand(s). The literal physical action of hitting or clapping.
楽しい場面でみんなで手を打って喜びを表した。
At the joyful moment, everyone clapped their hands to express delight.
演奏者の合図で観客が手を打った。
At the performer's cue, the audience clapped their hands.