| Noun | 1. | mouthpiece - a part that goes over or into the mouth of a person; "the mouthpiece of a respirator"aperture - an man-made opening; usually small | |
| 2. | mouthpiece - an acoustic device; the part of a telephone into which a person speaksphone, telephone, telephone set - electronic equipment that converts sound into electrical signals that can be transmitted over distances and then converts received signals back into sounds; "I talked to him on the telephone" | |
| 3. | mouthpiece - a spokesperson (as a lawyer)colloquialism - a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech | |
| 4. | mouthpiece - (especially boxing) equipment that protects an athlete's mouth | |
| 5. | mouthpiece - the tube of a pipe or cigarette holder that a smoker holds in the mouthpipe, tobacco pipe - a tube with a small bowl at one end; used for smoking tobacco tube, tubing - conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases | |
| 6. | mouthpiece - the aperture of a wind instrument into which the player blows directlyaperture - an man-made opening; usually small wind instrument, wind - a musical instrument in which the sound is produced by an enclosed column of air that is moved by the breath | |