a natural phenomena where two bros experience the same thing while at different locations or times, or something that is an extreme coincidence happens amongst bros. Its more than a coincidence, its a broincidence.
BRO 1: At approximately 10:37 P.M. EST on June 12th, I got it in with that hoe Amy
BRO 2: Dude bro, the same thing happened to me at the exact same time exactly one year ago!
BRO 1: Its a broincidence!
BRO 3: Bro! What are you doing here at the strip club?!?
BRO 4: Objectifying women, what about you?
BRO 3: Same!
BRO 4: What a broincidence!