pis·​ton | \ ˈpi-stən How to pronounce piston (audio) \

Definition of piston

 (Entry 1 of 2)

1 : a sliding piece moved by or moving against fluid pressure which usually consists of a short cylindrical body fitting within a cylindrical chamber or vessel along which it moves back and forth
2 : a sliding valve moving in a cylinder in a brass instrument which when depressed by a finger knob serves to lower the instrument's pitch


biographical name
Pis·​ton | \ ˈpi-stən How to pronounce Piston (audio) \

Definition of Piston (Entry 2 of 2)

Walter Hamor 1894–1976 American composer

Examples of piston in a Sentence

Recent Examples on the Web: Noun

The Holy Bible, by contrast, sounded harsh and claustrophobic; listening to it felt like being trapped in the bowels of a giant machine, surrounded by clanking pistons and rattling rivets and vats of bubbling oil. Longreads, "Manic Street Preachers’ Album The Holy Bible," 25 June 2019 If the two models are in fact equivalent, then the two pistons really are on track to get arbitrarily closer together. Quanta Magazine, "In Quantum Games, There’s No Way to Play the Odds," 1 Apr. 2019 All models have dual-disc four-piston Brembo front brakes, ABS, an electronic stability and traction control system, and USB charging ports. Alexander George, Popular Mechanics, "Indian’s New Motorcycle Is a Flat-Track Racer Built for the Road," 2 Oct. 2018 Battery-powered cars have far fewer parts than cars reliant on gasoline or diesel, endangering suppliers of valves, pistons and other parts in conventional engines. Jack Ewing, New York Times, "The Car Industry Is Under Siege," 6 June 2019 On June 1, Colorado native and pilot Kent Holsinger took off out of Leadville in a Lancair Super ES airplane powered by a 310-hp piston engine. Stephanie Butzer, The Denver Post, "Colorado native breaks record of fastest flight from Leadville to Death Valley," 6 June 2019 Enhancements to the engine relative to the 50i's unit include a block made of a new aluminum alloy, a viscous damper on the crankshaft, stronger pistons and piston rings, and an iron coating on the cylinder walls. Daniel Golson, Car and Driver, "The 2020 BMW X5 and X7 Get New M50i Performance Variants," 22 May 2019 That can cause abnormal combustion and damage pistons and connecting rods. Tom Krisher, The Seattle Times, "Hyundai finds new engine problem, prompting another recall," 30 Mar. 2019 The Korean automaker, under pressure from safety regulators, is recalling about 20,000 Veloster cars in the U.S. and Canada because fuel can prematurely ignite in the cylinders around the pistons. Tom Krisher, The Seattle Times, "Hyundai finds new engine problem, prompting another recall," 30 Mar. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'piston.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of piston


1704, in the meaning defined at sense 1

History and Etymology for piston


French, from Italian pistone, from pistare to pound, from Old Italian, from Medieval Latin, from Latin pistus, past participle of pinsere to crush — more at pestle

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Statistics for piston

Last Updated

11 Jul 2019

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Time Traveler for piston

The first known use of piston was in 1704

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English Language Learners Definition of piston

: a part of an engine that moves up and down inside a tube and that causes other parts of the engine to move


pis·​ton | \ ˈpi-stən How to pronounce piston (audio) \

Kids Definition of piston

: a disk or short cylinder that slides back and forth inside a larger cylinder and is moved by steam in steam engines and by the explosion of fuel in automobiles

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More from Merriam-Webster on piston

Rhyming Dictionary: Words that rhyme with piston

Spanish Central: Translation of piston

Nglish: Translation of piston for Spanish Speakers

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