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
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Last week Cirrus Aircraft announced the introduction of a new addition to its SR series of single-engine piston aircraft, the G7+, which will feature the company’s Safe Return Emergency Autoland technology as standard equipment. Jim Vinoski, Forbes.com, 22 May 2025 This information is sent to a computer that rapidly calculates the distortion, then adjusts pistons behind a deformable mirror to reshape the reflective surface in a way to compensate for the twinkling. Phil Plait, Scientific American, 15 May 2025 Aircraft manufacturer Cirrus is launching a new safety system in a single-engine piston airplane. Morgan Severson, CNN Money, 6 May 2025 Its distinguishing feature is the use of a jet engine, unlike other loitering munitions of similar size, which typically rely on piston engines. Vikram Mittal, Forbes.com, 29 Apr. 2025 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

Browse Nearby Words

Cite this Entry

“Piston.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/piston. Accessed 29 May. 2025.

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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