pis
ton
Plural
pistons
1
a solid, round part that moves back and forth inside a hollow tube in an engine or machine, helping to push or pull gases or liquids, or to turn pressure into movement
- The piston moves up and down inside the engine.
- Steam pushes the piston to power the machine.
- The piston turns heat energy into movement.
- The car engine has several pistons working together.
- A pump uses a piston to move water.
Synonyms: