Definition from Wiktionary, the free dictionary
- (intransitive, US) To become quieter
- As the lights dimmed the general noise quieted down.
- (intransitive, US) To reduce intensity of an activity.
- Diplomacy can only begin when the violence quiets down.
- (transitive, US) To make someone or something become quieter.
- The teacher did her best to quiet the children down.
- quieten down which is preferred usage in UK.