What is the meaning of Piston?

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)

A valve device in some brass instruments for changing the pitch

To move up and down or in and out like a piston.

genitive singular of pisto

piston

contact, connection

piston.

piston

piston

piston

Source: wiktionary.org