<p><strong>Noun</strong></p><ul><li>a piece placed at or forming the mouth, as of a receptacle or tube.</li><li>a piece or part, as of an instrument, to which the mouth is applied or which is held in the mouth: the mouthpiece of a trumpet.</li><li>the part of a bit or bridle, as for a horse, that passes through the animal's mouth.</li><li>a person, newspaper, etc., that conveys the opinions or sentiments of others; spokesperson.</li><li>Slang: a lawyer, especially a criminal lawyer.</li></ul>