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

Both hydraulic hoses run from the handlebar levers into that unit, with two other hoses running from the unit to the front and rear brake pistons. —Ben Coxworth, New Atlas, 11 July 2024

The whole thing collapsed like a piston over the course of likely a few days. —Erik Klemetti, Discover Magazine, 17 June 2024

Across all configurations, the principle is the same: a mix of fuel and air inside a cylinder is ignited, and the force of the resulting explosion forces a piston, which then turns a crank, allowing the vehicle to move. —Chris Gallagher, USA TODAY, 6 June 2024

Huff explains that, unlike a piston engine, a turbine engine compresses and then ignites the air-fuel mixture and blows the expanding gases past the turbine at an angle, which drives the shaft and generates power to move the vehicle. —Chris Gallagher, USA TODAY, 6 June 2024

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