your homies such as homeboys and homegirls who you've been through a lot with.. whther negative or positive. in other words, "the realests" of the real.
"Bredrin" is the Rastafarian subdialect word for Brethren. With original religious implications, the word later took on the Bible definition of "brother". Hence, one who shares a common ancestry, allegiance, character, or purpose with another.