1) to playfully strike someone in the sternum with your knuckles.
2)A girl in which a bro would like to tap.
3) A way of expressing yourself at pep rallies
4) to penetrate a fellow bro's anus with your penis and or other object (hand, black dildo, Statute of Liberty, Umbrella, or a watermellon)
* Oh dude you your bro tap took my breath away (example of def. 1 & 4)
* Guy 1: School Spirit!!!
Guy 2: Bro Tap (smacks Guy 1 in the sternum)
* Girl: I'm so drunk right now
Guy: wanna join me in a bro tap? (Example of 2)
* Guy: AHHHHHHHHH!!!!!! (Example 4)