quieten down

verb

The children need to quieten down before bedtime.

意味（1）

(intransitive, Britain) To become quieter.

As the lights dimmed the audience quietened down.

意味（2）

(intransitive, Britain) To reduce intensity of an activity.

Diplomacy can only begin when the violence quietens down.

意味（3）

(transitive, Britain) To make someone or something become quieter.

The teacher did her best to quieten the children down.