life preserver

a buoyant jacket, belt, or other like device for keeping a person afloat.

British Slang. a weapon, especially a short stick with a weighted head; blackjack.

Origin of life preserver

First recorded in 1630–40

As the life-preserver is a little out of repair, I stay on shore.

Punchinello, Vol. 1, No. 24, September 10, 1870 |Various
They let out lots of line, but still the life-preserver was towed away.

A Jolly Fellowship |Frank R. Stockton
Sarves him right, too, what business had he to grasp my life-preserver without leave.

The Attache |Thomas Chandler Haliburton
In teaching this stroke I revise both the back and the Dalton stroke with the life-preserver on.

Swimming Scientifically Taught |Frank Eugen Dalton and Louis C. Dalton

Still, hazarded Nelson, maybe he put the life-preserver on to save him from automobiles.

Four Afloat |Ralph Henry Barbour

life preserver

British a club or bludgeon, esp one kept for self-defence

US and Canadian a life belt or life jacket