When one "bro" (typically a frat boy) engages in a sexual act with another "bro", regardless of whether or not the two "bros" are actual biological relation.
When two people within a friendship group, especially two men within a fraternity, start dating and make hanging out as a group feel really weird
Ricky: dude it feels so weird since Johnnie and Marko started dating
Jo-dog: thats homophobic brah!
Ricky: nah dude, its not the gay thing, its just... *gazes off into middle distance* ...thats /brocest/ man
1. The act where more than one male, feels strongly about a particular issue in which other males are affected
1. " I can't believe that John posted all those pictures from the Bucks night on Facebook! I heard Mary demanded to see the pictures. We should Brotest against this action"