life‧sav‧er /ˈlaɪfseɪvə $ -ər/
noun [countable]1. someone or something that helps you avoid a difficult or unpleasant situation:
A microwave oven can be a real lifesaver when you’re pressed for time.2. someone or something that prevents you from dying:
The seat belt is the biggest single lifesaver in cars.3. a
lifeguard [TahlilGaran] Dictionary of Contemporary English ▲