1. to make or become quiet or calm
Usage: third person singular present tense of ‘quieten’; chiefly British

Examples

• The teacher quietens the noisy classroom with a gentle word.
• The medicine quietens her cough within minutes.
• He quietens the crying baby by singing softly.
• The storm gradually quietens as it moves away.
• She quietens her fears by taking deep breaths.
• The crowd quietens when the speaker approaches the podium.