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

Versus its 788 hp predecessor in the 812 Superfast, the engine spins up 31 more horses and gets titanium connecting rods that are 40 percent lighter, a lightened crankshaft and pistons, and valve-train components derived directly from Ferrari’s F1 engines, boosting mechanical efficiency. —Lawrence Ulrich, Robb Report, 1 Oct. 2024

The basic design was very simple: one static finger and a second that opened and closed the grip based on the motion of a hydraulic piston. —Jacek Krywko, Ars Technica, 23 Apr. 2024

Porsche's patent shows the crankshaft spinning within a ring on planetary gears, meaning as the crankshaft rotates, the pistons have two entirely different top-dead-center positions as well as two different bottom-dead-center positions. —New Atlas, 19 Sep. 2024

So the partition moves unidirectionally, right to left, like a piston expanding. —Quanta Magazine, 12 Sep. 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