piston

noun

pis·​ton ˈpi-stən 

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

The visible pistons are this shoe’s signature, and instantly recognizable worldwide. —Kristina Rutkowski, Vogue, 4 Apr. 2025

Consider a now-classic study, involving brain scans and fingers crushed by hydraulic pistons. —Peter Ubel, Forbes.com, 26 Mar. 2025

So there are things like individual throttle valves, dry sump lubrication, solid cam finger followers (instead of hydraulic valve lifters), titanium con rods, and forged pistons. —Ars Technica, 29 Jan. 2025

This is achieved essentially with large magnets, as opposed to steam pistons used on older American carriers. —Matthew Bodner, NBC News, 2 Mar. 2025

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

Phrases Containing piston

• piston pin
• piston ring
• piston rod

Kids Definition

piston

noun

pis·​ton ˈpis-tən 

: 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 

Walter Hamor 1894–1976 American composer