mouthpiece Meaning, Definition & Usage

  1. noun a part that goes over or into the mouth of a person
    • the mouthpiece of a respirator
  2. noun an acoustic device; the part of a telephone into which a person speaks
  3. noun a spokesperson (as a lawyer)
    mouth.
  4. noun (especially boxing) equipment that protects an athlete's mouth
    gumshield.
  5. noun the tube of a pipe or cigarette holder that a smoker holds in the mouth
  6. noun the aperture of a wind instrument into which the player blows directly
    embouchure.

WordNet

Mouth"piece` noun
Definitions
  1. The part of a musical or other instrument to which the mouth is applied in using it; as, the mouthpiece of a bugle, or of a tobacco pipe.
  2. An appendage to an inlet or outlet opening of a pipe or vessel, to direct or facilitate the inflow or outflow of a fluid.
  3. One who delivers the opinion of others or of another; a spokesman; as, the mouthpiece of his party. hence (slang) a person's lawyer
    Egmont was imprudent enough to make himself the mouthpiece of their remonstrance. Motley.

Webster 1913