A word or phrase in which the first few letters are replaced with "bro" in order to quantify or highlight how much of a bro the person/animal/object/activity in question is.
Bro 1: Sup brofessor?
Bro 2: Not much bromeo, I'm just here chillin', eatin' brotato chips.
Bro 1: Cool man, you going to the brodeo later?
Bro 2: Nah bro, I've got a party with my dawgs from West Coast Brollege to go to.
Bro 1: Be as bromiscuous as possible, and use brotection.
Bro 2: Will do broseidon, later bromie.
Bro 1: Time to play some Super Mario Bros. Mario is the brotagonist of that game. His brother is Luigi.
Bro 2: In the above exchange we used many a brolloquialism!