pis·ton | \ˈpi-stən \

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 \

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

According to museum president Paul Schneider, the Silsby engines used rotary gears instead of pistons, the common feature of the time. Mark Yost, WSJ, "A Museum to Spark New Interest," 11 July 2018 In higher gears, where the stretch from 8000 to 9000 rpm grows to more than a fraction of a second, the churn of its six pistons exactly mimics the characteristic buzz-saw sound of an Airbus A320’s turbofan engines at takeoff. James Lipman, Car and Driver, "2018 Porsche 911 GT3 PDK Automatic," 23 Mar. 2018 His powerful muscles seemed to uncoil, and his shoulders, like oversize pistons, drove us forward, springing over the sand as though a 160-pound man weren’t on his back. Peter Gwin, WSJ, "The Horses That Changed History," 19 June 2018 But at age 93, even Kelly, one of the pistons in the long-ago Daley machine, can’t get a park named in his honor. Morgan Greene, chicagotribune.com, "Why a ward boss in the Daley machine is having a hard time getting a park named for him," 8 June 2018 The engine-rebuild kit—including pistons, rings, bearings, oil pump, and timing belt—was $245. Car and Driver, "The Battle of the Off-Road Beaters: Ford F-150 Custom vs. Geo Tracker, Jeep Cherokee, Land Rover Discovery," 30 Nov. 2016 Smaller piston skirts cut 27 grams while the connecting rods are 41 grams lighter. Jeff Yip, Houston Chronicle, "2019 Mazda MX-5 gets 26-hp boost," 23 June 2018 Up against a wall in the Amber Lab is a robot that bounces up and down a scaffolding like a piston. Matt Simon, WIRED, "Inside the Mad Lab That's Getting Robots to Walk and Jump Like Us," 14 June 2018 In one of the most ferocious performances of the night, Christiana Perrault pistons her hips in a black fringe miniskirt cut to the moon as Turner. Andrea Simakis, cleveland.com, "'The Royale,' inspired by boxer Jack Johnson, brings fight for freedom to stage (preview)," 13 May 2018

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

19 Sep 2018

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Time Traveler for piston

The first known use of piston was in 1704

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More Definitions for piston



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 \

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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Spanish Central: Translation of piston

Nglish: Translation of piston for Spanish Speakers

Comments on piston

What made you want to look up piston? Please tell us where you read or heard it (including the quote, if possible).


evasion of direct action or statement

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