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

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

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