reliever

noun

1. Something which relieves (pain, etc.).

   “Pepto-Bismol is an upset-stomach reliever.”

2. A relief pitcher.

   “The first reliever got the last two outs of the sixth.”

3. Someone who fills in for another.

   “I'll be the reliever today so that you can each take a break.”

4. (dated, slang)A garment kept for being lent out.

   “Now that fellow wants five or ten dollars on his suit. He goes to this pawn shop and asks for a reliever. That is a second-hand suit, pretty well used up.”