Contrary to popular belief, homeboy along with homie were both created by Chicano aka Mexican American Pachucos from the word "Hombre" which is spanish for "man". It all derived from the slang they used known as "Calo".

closest friend

A close friend.

Originally used among transplanted African-Americans with Southern roots to refer to and aid in the assimilation of someone who might have directly migrated from a common Southern home town or is otherwise well known to the person using the term.

Used to establish a mutual relationship between the invidividual using the term, the person described by it, and a third person.

Guy to chill with. long-time friend.

The epitome of a friend. Somebody you kick it with. A person who always has your back. You can't go through life without a homeboy. It's hard to have more than one, because they're one in a million.

A vessel for spreading news, especially in the case of perps snatchin' yo people up, tryin' to rape 'em.

In the California Prison system a "Homeboy" is someone from the same race and county you are from whom you are on good terms. Your "Home" town etc