Mouthwash (noun)

1. A liquid that is used as a rinse or gargle to freshen the breath, kill germs, and clean the mouth.
2. A medicated liquid used to clean the teeth and gums.

Origin:

Early 20th century: from mouth + wash.

Examples:

1. He used mouthwash to freshen his breath before the meeting.
2. She recommended using a fluoride-based mouthwash to strengthen the teeth.
3. The mouthwash had a strong minty flavor.
4. Mouthwash is an effective way to kill germs and freshen the breath.
5. The mouthwash was used as a final rinse after brushing the teeth.