1. to behave in an inappropriate, unethical, or unacceptable manner
He acted badly during the meeting and offended several colleagues.
Ele se comportou mal durante a reunião e ofendeu vários colegas.
2. to perform poorly or inadequately in a role or situation
The actor acted badly in that scene and had to do multiple takes.
O ator atuou mal naquela cena e teve que fazer várias tentativas.
3. to misbehave or conduct oneself improperly
The children acted badly and were sent to their rooms.
As crianças se comportaram mal e foram mandadas para seus quartos.