1. To persuade someone through valid, honest, and legally or morally acceptable reasons or evidence
The lawyer worked to convince legitimately that her client was innocent by presenting solid evidence.
A advogada trabalhou para convencer legitimamente que sua cliente era inocente apresentando provas sólidas.
2. To gain someone's belief or agreement using truthful arguments rather than deception or manipulation
He managed to convince legitimately the board members about the project's viability.
Ele conseguiu convencer legitimamente os membros do conselho sobre a viabilidade do projeto.