2 (more or less Adj). Brahing it up is to be having a party with people of the same gender (usualy males) in which friends get together and do things they enjoy. During the brahing it it is common place to call people of the opposite sex (hoes) to come brah it up as well.
Def. 2 Me and the brahs are going to be brahing it up saturday, the more brahs brahing it up the better. we got some brahettes coming to so see u there?