also: アイスブレイカー
noun
A game, activity, or remark used to relieve tension and help people get to know each other, especially at the start of a meeting, party, or workshop.
研修の最初にアイスブレーカーとして自己紹介ゲームをした。
At the beginning of the training, we played a self-introduction game as an icebreaker.
彼の冗
His joke served as a good icebreaker.