This is the 6753rd most frequent Portuguese word.
gilberto
"Gilberto" is a Portuguese male given name, equivalent to "Gilbert" in English.
Here, 'Gilberto' is used as a proper noun to refer to a person by name.
Gilberto é um excelente músico.
Gilberto is an excellent musician.
In this instance, 'Gilberto' is used as a direct object indicating the person to whom the action of 'told' is directed.
Eu disse ao Gilberto que chegaria atrasado.
I told Gilberto that I would arrive late.
Here, 'do Gilberto' indicates possession, showing that the store belongs to Gilberto.