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Definition of "piston" [pis•ton]

  • A solid cylinder or disk that fits snugly into a larger cylinder and moves under fluid pressure, as in a reciprocating engine, or displaces or compresses fluids, as in pumps and compressors. (noun)
  • Music A valve mechanism in brass instruments for altering the pitch. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Use "piston" in a sentence
  • "But Black has size on his side and keeps forcing him against the ropes, getting in short piston blows into his ribs, which seem to move with a life of their own after the first blow."
  • "(enquiry) bears upon the face of it the stopping (istanai) of the stream; and the word piston (faithful) certainly indicates cessation of motion; then, again, mneme (memory), as any one may see, expresses rest in the soul, and not motion."
  • "The type IV secretory system is an elaboration of the type II, except now the piston is a long filament, and that filament can stick to surfaces."