I found in the Urbandictionary this definition.. I don't know if is correct, our buddies could explain us better...
Someone you grew up with, friend or not, and someone with whom you have shared any number of bonding experiences at home, in school, at work, or in any close-knit atmosphere. Homie means you have lived in the same area as this person for a significant amount of time in your life, but the term is appropriately used by those friends who truly feel comfortable referring to each other with such respect. It isn't a word that should be taken advantage of, because a person recognizes who is a friend and who isn't. Therefore, a true homie is always down, while lesser friends will just be out to use you, borrow money from you, bum a ride in your car, etc.
Example: Yo, homie, I'll be at my house incase you want to come kick it later
See ya..fella !!!!