An inflatable belt, generally of india-rubber, or a belt made of several pieces of cork fastened together, used to support the body in the water.(noun)
The Century Dictionary (Public Domain)
Use "life-belt" in a sentence
"Kai asked as he placed the life-belt for the heavy-worlder by the seismimic."
"Meg-I'm just glad the "life-belt" isn't made of brass and iron!"
"It is not good policy to start by telling them to throw away the life-belt."