quiet down

[Konrador 0]

become quiet or quieter

[Carollacob]

To quiet down means to reduce noise or activity to a calmer, more subdued level. It can be directed towards people who are being too loud or disruptive, asking them to lower their voices or cease their disruptive activities. It can also describe a situation or environment that has transitioned from being noisy or busy to being more peaceful and still.

[Kai]

To reduce intensity of an activity.

[Zipporah Schumaker]

To make someone or something become quieter.