Since the authoritative resource on connotational and colloquial meanings of words seems to be Urban Dictionary, I'll take some quotes.
Adding onto this, according to a lot of different forumers, many black people use it in everyday conversation as a replacement for things like "bro" and "dude," completely stripping it of the offensive nature of the term and going back to its original roots. (The term was originally a neutral term referring to black people.
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I haven't seen this myself, but you have to know that this is a word whose definition varies widely from person to person, to some it means nothing, to some it's unacceptable to use it at all. You really can't place a universal definition on it because everyone uses it differently.