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 rear uses a 220mm disc with a Nissin two-piston caliper. —Josh Max, Forbes.com, 12 June 2026

Basically, the liquid metal droplet simultaneously acts as the motor, piston, and actuator. —New Atlas, 12 June 2026

The second, DuAlumin3D, is a 3D-printable alloy developed for pistons. —Chris Young, Interesting Engineering, 12 June 2026

Devers remains the most important piston in the engine block, but the time might be fast approaching when Eldridge overtakes him. —Andrew Baggarly, New York Times, 5 June 2026

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

Rhymes for piston

• cystine

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