Zan-shin in jujitsu (classical Japanese martial art, usually referring to fighting without a weapon) means the preparedness to make the next attack, such as pulling back the fist at the speed faster than that of landing a bow, and not losing balance even after throwing the opponent.
柔術における残心は、拳は繰り出すスピードより早く引き戻す、相手を投げた後もバランスを崩さないなど次の攻撃の準備ができていることを意味する。