piston ring

American  

noun

1. a metallic ring, usually one of a series, and split so as to be expansible, placed around a piston in order to maintain a tight fit, as inside the cylinder of an engine.

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piston ring British  

noun

1. a split ring, usually made of cast iron, that fits into a groove on the rim of a piston to provide a spring-loaded seal against the cylinder wall

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Etymology

Origin of piston ring

First recorded in 1865–70

Example Sentences

The companies most endangered may be small machine shops in Michigan or Ontario that produce piston rings and other parts.

From New York Times

The piston rings may not have been properly heat-treated, which can cause engine damage, oil leaks and possible fires.

From Seattle Times

Mr. Carlisle, the racer, said the Ford engine that had been in his Mustang required new bearings and piston rings after every race.

From New York Times

Then Uncle Hermilio asked Lucky about his car, and Lucky started talking about valves and piston rings and carburetors.

From Literature

He rested his hand on a rack of piston ring installers and timing gear pullers, and this man who lost so much of his family to hurricanes started talking about the parts of them.

From The Guardian