What does Primo mean in English?

What does Primo mean in English?

(Entry 1 of 3) : the first or leading part (as in a duet or trio)

Does Primo mean brother?

So, by calling your buddy your primo in Spanish, you are essentially conveying your closeness with the person. In this case, the translator felt that for English speakers, the message of closeness between the two characters would be better conveyed through the use of the word "brother."