piston ring



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.

Nearby words

  1. pistolier,
  2. pistology,
  3. piston,
  4. piston engine,
  5. piston pin,
  6. piston rod,
  7. piston slap,
  8. piston, walter,
  9. pistou,
  10. pisé

Origin of piston ring

First recorded in 1865–70

Also called packing ring, ring.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for piston ring

British Dictionary definitions for piston ring

piston ring


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
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012