Noun
main man (plural main men)
(idiomatic, chiefly African-American Vernacular) One's closest male friend.
My other Main Man is Muhamed Ali, for the obvious reasons. Randy Castillo
Hugh Grant is the main man. He's the number one romantic comedy man in the world. Sam Elliott
There are a lot of heroes and villains across the galaxy, but there is only one "Main Man." Source: Internet