1. the lower jaw of a person or animal

Examples

• The dentist examined her underjaw for signs of decay.
• The dog’s underjaw protruded slightly beyond the upper jaw.
• He felt pain in his underjaw after the dental procedure.
• The fossil showed a well-preserved underjaw from an ancient mammal.
• She massaged her underjaw to relieve the tension.
• The boxer took a hard hit to his underjaw during the match.