1. In a way that shows respect, deference, or esteem
I respectfully disagree with your opinion.
Respeitosamente discordo da sua opinião.
2. Politely and courteously, especially when expressing disagreement or making a request
She respectfully requested a meeting with the manager.
Ela respeitosamente solicitou uma reunião com o gerente.
3. Used as a formal closing in letters or formal communications
Respectfully yours, John Smith
Atenciosamente, João Silva