1. to stop doing something that you do regularly, especially something that is difficult to stop
I'm trying to break the habit of drinking coffee late at night.
Estou tentando quebrar o hábito de beber café tarde da noite.
2. to successfully eliminate a repetitive or compulsive behavior
She finally managed to break the habit of biting her nails.
Ela finalmente conseguiu quebrar o hábito de roer as unhas.