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.
- A part, as of a musical instrument or a telephone, that functions in or near the mouth.
- Sports A protective rubber device worn over the teeth, as by boxers.
- Informal One, such as a spokesperson, through which views are expressed.
- Slang A defense lawyer.