friend 1: who are those random bro's that just came in?  friend 2: oh, those are just the bro overflow
"the 2 or 3 random bro's that always show up at your party due to the overflow of bro's at other parties
"friend 1: who are those random bro's that just came in?  friend 2: oh, those are just the bro overflow" What is the definition of "bro overflow"?