lifebelt (also lifebuoy)

n ring of buoyant or inflatable material used to keep afloat a person who has fallen into water 救生圈.

life sciences, life story, life work, life-and-death (also life-or-death), life-blood, life-boat, life-giving, life-guard, life-jacket, life-preserver, life-raft, life-saver, life-saving, life-size, life-size, life-sized, life-span, life-style, life-support, life-time, life-work, lifeboat, lifeless, lifelessly, lifelessness, lifelike, lifeline, lifelong, lifer, lifestyle, lifetime, lift, lift-attendant, lift-off, ligament, ligature, light, light bulb, light industry, light meter, light pen,