1. to regain mental clarity, composure, or focus after confusion, intoxication, or emotional distress
After a good night's sleep, she became clear-headed and able to make rational decisions.
Após uma boa noite de sono, ela ficou com a cabeça clara e conseguiu tomar decisões racionais.
2. to achieve a state of mental alertness and sharp thinking
He needed coffee to become clear-headed before the important meeting.
Ele precisava de café para ficar com a cabeça clara antes da reunião importante.