1. A Male in a wedding who is the Brother of the Groom, but not the Best Man.
2. A Dude in the wedding who is a Bro of the Groom.
3. A Bro in the wedding who is a Dude of the Groom.
4. Closer than a Groomsman to the Groom.
Dude, You have too much awesome to be a groomsman, you must be a GroomsBro...Bro!
Hey Nerd, you cant be a GroomsBro...Bro!
Bro, will you be my GroomsBro?
Dude, will you be my GroomsBro?