1. to regain control of one's emotions; to become calm and collected after being upset, stressed, or agitated
After hearing the bad news, she took a deep breath to compose herself before speaking.
Depois de ouvir a má notícia, ela respirou fundo para se acalmar antes de falar.
2. to arrange one's thoughts or demeanor in a controlled manner
He composed himself and walked into the meeting with confidence.
Ele se compôs e entrou na reunião com confiança.