warm up phr v 1 [I,T] to become warm or hot, or to make something warm or hot （使）变暖［热］: The weather's starting to warm up. 天气开始暖和起来。 2 [I,T] to do gentle exercises to prepare your body before doing a sport, dancing etc 做准备活动，热身: The athletes were warming up for the race. 运动员在为比赛做热身运动。 3 [I] if a machine warms up, it becomes ready to work properly 〔机器〕预热