piston

noun

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

Examples of piston in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Bryan’s previous records have wallowed in the recent past; Young Manhood uses it like a piston into the future. — Grayson Haver Currin, Pitchfork, 20 Oct. 2026 Braking is handled by dual-piston hydraulic calipers clamping down on large rotors for the promise of serious stopping power even in wet weather. — New Atlas, 19 Oct. 2026 Its boosted flat-six engine receives a power bump, and rear-axle steering is now standard, as are larger brakes with six-piston calipers up front. — Bradley Iger, Robb Report, 16 Oct. 2026 His steam turbine could generate power far more cheaply, and on a vastly greater scale, than traditional piston engines. — Chang Che, New Yorker, 24 Sep. 2026 See All Example Sentences for piston

Word History

Etymology

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

First Known Use

1704, in the meaning defined at sense 1

Time Traveler
The first known use of piston was in 1704

Phrases Containing piston

Rhymes for piston

See All Rhymes for piston

Browse Nearby Words

pistol-whip
piston
Piston
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Cite this Entry

“Piston.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/piston. Accessed 27 Oct. 2026.

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Kids Definition

piston

noun
pis·​ton ˈpis-tən How to pronounce piston (audio)
: a sliding piece moved by or moving against the pressure of a fluid (as steam or hot gases) that usually consists of a short solid cylinder moving within a larger hollow cylinder

Biographical Definition

Piston

biographical name

Pis·​ton ˈpi-stən How to pronounce Piston (audio)
Walter Hamor 1894–1976 American composer
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