pis·​ton ˈpi-stən How to pronounce piston (audio)
: 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
: 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 Carl Jung’s great ally turned rival, Sigmund Freud, proposed a model of the human psyche that acted much like a machine—repression and projection as twin pistons in the psychic engine. Frederick Kaufman, Harper's Magazine, 26 Feb. 2024 High-performance sports cars will also use iron brake rotors but often utilize aluminum calipers with multiple pistons. Michael Harley, Forbes, 28 Feb. 2024 With traditional brakes, the calipers’ pistons are arranged radially. Lawrence Ulrich, Robb Report, 20 Feb. 2024 Manually operated pistons pulled the water from the reservoir and pumped it through the windkessel. Jennifer Ouellette, Ars Technica, 23 Jan. 2024 None of the intrusions affected industrial control systems that operate pumps, pistons or any critical function, or caused a disruption, U.S. officials said. Joseph Menn, Washington Post, 11 Dec. 2023 Most quarterbacks do not have legs like pistons; few of them can squat six hundred pounds. Louisa Thomas, The New Yorker, 28 Oct. 2023 When a compressing piston malfunctioned, the two men were crushed. Kurtis Lee, New York Times, 23 Nov. 2023 Powered by a spring piston with a break barrel, this air rifle can reach speeds of 1,250 feet-per-second with a .177 caliber pellet. T. Logan Metesh, Field & Stream, 4 Oct. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'piston.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

Dictionary Entries Near piston

Cite this Entry

“Piston.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/piston. Accessed 12 Apr. 2024.

Kids Definition


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


biographical name

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

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