To become loose; to loosen; to relax (a muscle, etc.).
To relax; to act less seriously.
To do gentle exercise, stretching etc., in order to prepare the body for more vigorous exercise.
To reach, or cause to reach, a normal operating temperature (of a car for example).
To become warmer.
To heat or reheat (e.g. food).
To make (an audience) enthusiastic or animated before a show
To prepare for an activity by carrying out a practice or preparation routine.