ichidan verb, transitive verb
calm down; settle down; compose
Transitive verb meaning to make someone or something calm, quiet, or settled. Often used for calming a person, a situation, or one's own feelings.
興奮している子供を落ち着けるのに苦労した。
I had trouble calming down the excited child.
まず気持ちを落ち着けてから話しましょう。
Let's talk after you've composed yourself first.