A solid disk or cylinder that fits inside a hollow cylinder, and moves under pressure (as in an engine) or displaces fluid (as in a pump)

(firearms); (intransitive) To move up and down or in and out like a piston.

plural of piston

A surname.

simple past tense and past participle of piston

Having (a particular kind or number of) pistons.

present participle of piston

A surname.

plural of Pistone

A ring or seal that fits around a piston, sealing between the piston and the bore in which it slides.