The required space between two males when they are forced to sit next to each other; the most frequent required space is that of an empty chair or couch space on either side of the first bro.
Dan went to sit next to Bill at the movies, but Bill immediately recognized the need for Bro Space since there were two empty seats to his right and left.
The space around a male's favorite part of his body (usually his genitals). Usually used when someone touches that space.
After Eric bumped into John's ass, John turned around and yelled "Dude give me my Bro-space! Seriously!"