1. Acting in a rude, impolite, or disrespectful manner; not following proper rules of conduct
The badly behaved child was sent to time out.
A criança mal-educada foi colocada de castigo.
2. Misbehaving; displaying improper or unacceptable conduct
The passengers were arrested for being badly behaved on the flight.
Os passageiros foram presos por se comportarem mal no voo.