1. conduct that is proper, well-mannered, and socially acceptable; adherence to rules and standards of conduct
The student was rewarded for good behavior in class.
O aluno foi recompensado pelo bom comportamento na aula.
2. in legal context, a reduction in sentence or early release from prison based on compliance with prison rules
He was released on good behavior after serving two years.
Ele foi libertado sob bom comportamento após cumprir dois anos de pena.