1. the part of a musical instrument, telephone, or other device that is placed in or near the mouth
2. a person who speaks publicly for a group or organization
Usage: often implies lack of independent thought
3. a protective device worn over the teeth during sports

Examples

• The trumpet player cleaned his mouthpieces after each performance.
• She replaced the old telephone’s cracked mouthpiece.
• The senator became the party’s primary mouthpiece on healthcare issues.
• Critics accused him of being nothing more than a mouthpiece for corporate interests.
• All hockey players are required to wear mouthpieces during games.
• The dentist recommended custom-fitted mouthpieces for the boxing team.
• The clarinet’s mouthpieces need to be soaked before playing.