1. a pitcher who does not start the game
Synonym: relief pitcherfireman
2. a person who reduces the intensity (e.g., of fears) and calms and pacifies
e.g. a reliever of anxiety
an allayer of fears
Synonym: allayercomforter
3. someone who takes the place of another (as when things get dangerous or difficult)
e.g. the star had a stand-in for dangerous scenes
we need extra employees for summer fill-ins