piston Meaning, Definition & Usage

  1. noun United States neoclassical composer (1894-1976)
    Walter Piston.
  2. noun mechanical device that has a plunging or thrusting motion
    plunger.

WordNet

Pis"ton noun
Etymology
F. piston; cf. It. pistone piston, also pestone a large pestle; all fr. L. pinsere, pistum, to pound, to stamp. See Pestle, Pistil.
Definitions
  1. (Mach.) A sliding piece which either is moved by, or moves against, fluid pressure. It usually consists of a short cylinder fitting within a cylindrical vessel along which it moves, back and forth. It is used in steam engines to receive motion from the steam, and in pumps to transmit motion to a fluid; also for other purposes.

Webster 1913