Definition of piston in English:

Share this entry


Pronunciation: /ˈpɪst(ə)n/


Image of piston
1A disc or short cylinder fitting closely within a tube in which it moves up and down against a liquid or gas, used in an internal combustion engine to derive motion, or in a pump to impart motion.
Example sentences
  • Besides leaving salt deposits, rusting internal parts and causing valve damage, water in an engine also makes short work of pistons and cylinders.
  • The central control circuit then sends a control signal to the driver's circuit for the accumulator piston.
  • The aluminum block has ductile iron cylinder liners and is filled with JE pistons.
1.1A valve in a brass musical instrument in the form of a piston, depressed to alter the pitch of a note.
Example sentences
  • It is in C, a tone above the euphonium, and reaches the lowest notes with the aid of six pistons; its upward range is much greater than that of the larger tubas.
  • The valves and pistons on a trumpet are very delicate - and essential.


Early 18th century: from French, from Italian pistone, variant of pestone 'large pestle', augmentative of pestello 'pestle'.

  • The Latin pistullum meant pestle (Middle English) and is the source of the botanical pistil (early 18th century) from its similar shape. From the same source Italian formed pestone for a large pestle or rammer, and this, via French, is the source of piston.

Words that rhyme with piston

cistern, Liston, Wystan

For editors and proofreaders

Line breaks: pis¦ton

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.