1. A person who is mischievous, impudent, or behaves in a roguish manner; often used affectionately or as mild criticism
That rascal stole my sandwich!
Aquele lascão roubou meu sanduíche!
2. A person with a lusty or lascivious nature; someone prone to indulgence
He's quite the rogue when it comes to chasing women.
Ele é um lascão quando se trata de conquistar mulheres.