reliever

UK: rɪˈliːvə | US: rɪˈliːvər

Definition
  1. n. a person or thing that relieves or alleviates something (e.g., pain, stress, or a difficult situation)

  2. n. (baseball) a pitcher who replaces the starting pitcher during a game

  3. n. (informal) something that provides comfort or relaxation

Structure
relieve <to ease or alleviate>er <agent noun suffix>
Etymology

The word "reliever" originates from the verb "relieve," which comes from Old French "relever" (to raise, lighten) and Latin "relevare" (to lift again, alleviate). The suffix "-er" is an English agentive suffix, indicating a person or thing that performs the action. Thus, a "reliever" is literally "one who relieves"—someone or something that lessens a burden or provides relief. The baseball sense emerged in the early 20th century, metaphorically extending the idea of "alleviating" the starting pitcher's workload.

Examples
  1. The doctor prescribed a pain reliever for her headache.

  2. The team's star reliever closed the game with three strikeouts.

  3. A warm cup of tea can be a great stress reliever after a long day.

  4. The new policy acted as a reliever for the financial strain on small businesses.

  5. Laughter is often called the best natural reliever of tension.