lifesaver

noun
1
a thing that helps somebody in a difficult situation; something that saves somebody’s life
فرشته نجات, نجات‌دهنده, نجات‌بخش, منجی
2
a person who is employed at a beach or a swimming pool to rescue people who are in danger in the water
نجات غریق, غریق‌نجات, منجی غریق