in action 1. 在积极活动中 Our baseball team was in action tonight. 今晚我们的棒球队打出了水平。 He is a very good table tennis player; you really ought to see him in action. 他是个出色的乒乓球运动员，你实在应该看他打球。 2. 在起作用；在运转中 The motor is not yet in action. 发动机还没开始运转。 3. 在战斗中 be killed in action 阵亡