mouthpiece

noun

A part, as of a musical instrument or a telephone, that functions in or near the mouth.

A rubber or flexible plastic protective device worn over the teeth, as by boxers.

One, such as a spokesperson, through which views are expressed.

A lawyer.

In an instrument or utensil made to be inserted or applied to the mouth, the part which touches the lips or is held in the mouth, as in a musical instrument, a tobacco-pipe, cigar-holder, etc. See cut under clarinet.