reliever
noun /rɪˈliːvə(r)/
  /rɪˈliːvər/
- (especially in compounds) a thing or person that removes or reduces pain, feelings of worry or unhappiness, or a problem - a pain reliever (= a drug used to reduce or remove pain)
- Exercise can be a great stress reliever.
 
- (also relief pitcher)(in baseball) a pitcher (= the player who throws the ball) who enters the game in place of the previous pitcher- Wilson began his major-league career as a reliever.
- The manager often has relievers warming up when the game starts.