best man
US /ˌbest ˈmæn/
UK /ˌbest ˈmæn/

1.
padrinho
a male friend or relative who attends the bridegroom at a wedding, and is usually his chief attendant
:
•
My brother asked me to be his best man at his wedding.
Meu irmão me pediu para ser seu padrinho em seu casamento.
•
The best man gave a funny speech at the reception.
O padrinho fez um discurso engraçado na recepção.