piston

[pis-tuh n]

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noun

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.

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

Origin of piston

1695–1705; < French < 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) + -one augmentative suffix

Related formspis·ton·like, adjectivesub·pis·ton, noun

Piston

[pis-tuh n]

noun

Walter,1894–1976, U.S. composer.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for piston

cylinder, generator, transformer, turbine, tool, appliance, instrument, motor, weapon, diesel, mechanism, piston, apparatus, means, pot, fan, contrivance, agent, dynamo, barrel

Examples from the Web for piston

Historical Examples of piston

He employed a cylinder 12 centimeters in diameter fitted with a piston.
Scientific American Supplement, No. 417
Various
If steam is forced into the cylinder the piston will be forced to the opposite end of the cylinder.
Boys' Book of Model Boats
Raymond Francis Yates
It will be seen that a groove, M, is cut around the piston near the top.
Boys' Book of Model Boats
Raymond Francis Yates
The momentum of the flywheel A pushes the piston upward, closing these holes.
Boys' Book of Model Boats
Raymond Francis Yates
This cylinder block is soldered to the piston as shown in Fig. 56.
Boys' Book of Model Boats
Raymond Francis Yates

British Dictionary definitions for piston

piston

noun

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

Word Origin for piston

C18: via French from Old Italian pistone, from pistare to pound, grind, from Latin pinsere to crush, beat

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for piston

1704, from French piston, from Middle French piston "large pestle," from Old Italian pistone "a piston," variant of pestone "a pestle," from pestare "to pound," from Late Latin pistare, frequentative of Latin pinsere (past participle pistus) "to pound" (see pestle). As a verb from 1930.

piston in Science

piston

[pĭs′tən]

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.