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.
The rear uses a 220mm disc with a Nissin two-piston caliper. — Josh Max, Forbes.com, 12 June 2026 The single front electric motor is quicker and more torquey than the hybrid off the line, and silent with no moving pistons. — Cyril Soliman, The Drive, 27 May 2026 At that point, a piston forces oil upward through small or large openings and valves, depending on the velocity of the impact. — Stephanie Pearson, Wired News, 3 June 2026 While the driver was investigating, both pistons failed. — Jonathan Franzen, New Yorker, 1 June 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 7 Jul. 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

More from Merriam-Webster on piston

Nglish: Translation of piston for Spanish Speakers

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