It is a meaning derived from the street slang "brother", which most Jamaicans and South Londoners use. It is also a variation of the more familiar word "bruv".
A person who is a fan of Sam and Colby and they are very nice people that will always support you, unless you disrespect Sam and Colby then we're gonna go off. But otherwise they are very nice people and will always be there for you.
Phrase taken from the movie human traffic, used commonly by the ecstacy takers of Newcastle. It is said to a mate in recognition of something cool that was done or said.