Meaning good friends, similar to bro. The origin although believed ot be from anchorman is actually from, The Jamie Foxx Show. Braxton would always call Jamie brosef.
A bro, who notices there are too many nerds at a party and kicks them out into the cold for the sake of the hosts street cred and to create a enhanced party atmosphere. Reminiscent of Stalin exiling academics to Siberia for the stability of the USSR.