Source : WordNet®

warm up
     v 1: run until the normal working temperature is reached; "We
          warmed up the car for a few minutes"
     2: become more friendly or open; "She warmed up after we had
        lunch together"
     3: get warm or warmer; "The soup warmed slowly on the stove"
        [syn: {warm}]
     4: cause to do preliminary exercises so as to stretch the
        muscles; "The coach warmed up the players before the game"
     5: make one's body limber or suppler by stretching, as if to
        prepare for strenuous physical activity [syn: {limber up},
         {loosen up}]