- 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
- Walter,1894–1976, U.S. composer.
Examples from the Web for piston
He employed a cylinder 12 centimeters in diameter fitted with a piston.
If steam is forced into the cylinder the piston will be forced to the opposite end of the cylinder.
It will be seen that a groove, M, is cut around the piston near the top.
The momentum of the flywheel A pushes the piston upward, closing these holes.
This cylinder block is soldered to the piston as shown in Fig. 56.
- 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 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.
- 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.