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

While this design may decrease performance figures at lower speeds, the explanation continues, ignition efficiency ratings spike significantly when that piston starts to drop. —Kristin Shaw, Popular Science, 5 Dec. 2024

In a heady three months starting in May, the piston plane shot down at least a dozen Russian drones. —David Axe, Forbes, 28 Nov. 2024

At the forefront is the Jackie 1961 small shoulder bag, an enduring classic with a sleek, curved silhouette and piston hardware that harks back to its original 1950s design, a favorite of Jackie Kennedy herself. —Lilah Ramzi, Vogue, 27 Nov. 2024

The driver presses the brake pedal and hydraulic fluid is pushed down the brake lines into the caliper, expanding the pistons and pushing the brake pads against the rotor, slowing down the rotation of the rotor connected to the hub, thus slowing down the wheel. —New Atlas, 25 Nov. 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