piston

¹ American  

[pis-tuhn] / ˈpɪs tən /

noun

1. a disk or cylindrical part tightly fitting and moving within a cylinder, either to compress or move a fluid collected in the cylinder, as air or water, or to transform energy imparted by a fluid entering or expanding inside the cylinder, as compressed air, explosive gases, or steam, into a rectilinear motion usually transformed into rotary motion by means of a connecting rod.

2. a pumplike valve used to change the pitch in a cornet or the like.

---

Piston ² American  

[pis-tuhn] / ˈpɪs tən /

noun

1. Walter, 1894–1976, U.S. composer.

---

piston British  

/ ˈpɪstən /

noun

1. a disc or cylindrical part that slides to and fro in a hollow cylinder. In an internal-combustion engine it is forced to move by the expanding gases in the cylinder head and is attached by a pivoted connecting rod to a crankshaft or flywheel, thus converting reciprocating motion into rotation

---

piston Scientific  

/ pĭs′tən /

1. A solid cylinder or disk that fits snugly into a hollow cylinder and moves back and forth under the pressure of a fluid (typically a hot gas formed by combustion, as in many engines), or moves or compresses a fluid, as in a pump or compressor.

---

Other Word Forms

• pistonlike adjective
• subpiston noun

Etymology

Origin of piston

First recorded in 1695–1705; from French, from Italian pistone “piston,” a learned alteration of pestone “large pestle,” equivalent to pest(are) “to pound” (variant of Medieval Latin pistare, derivative of Latin pīstus, past participle of pīnsere “to pound, crush”) + -one augmentative suffix

Example Sentences

The higher forces, in turn, would require thicker piston crowns, shortened connecting rods and thicker wrist pins.

From The Wall Street Journal

It was also blended into gasoline to improve engine performance by preventing pistons from "knocking."

From Science Daily

At least Honda is acknowledging the emotional vacancy left from the absence of pistons, flame and fuel, and making an effort to fill it.

From The Wall Street Journal

The piston faces have small, crescent-shaped reliefs into which the valves extend near the top dead center.

From The Wall Street Journal

Many municipalities across the country have banned two-stroke leaf blowers—so named because a piston in a leaf blower engine makes two movements instead of four, as in a car.

From The Wall Street Journal

Related Words

• appliance
• diesel
• generator
• instrument
• motor
• power plant
• tool
• transformer
• turbine
• weapon