1. A person who has reached the legal age of adulthood, typically 18 years old, and is considered legally responsible and capable of making their own decisions
She became a legal adult on her eighteenth birthday.
Ela se tornou maior de idade no seu décimo oitavo aniversário.
2. Adjective form describing someone who has reached the age of legal majority
Only adults can vote in this election.
Apenas maiores de idade podem votar nesta eleição.