Used to signify to others that an individual is just a bro. No more, no less.
Dude, is it true you have a thing for Jennifer?
Nah man, she's jab.
Jab? As in she's just a bro?
Took the words right outta my mouth
Hey, do you have a thing for Billy?
Nahhh, hes jab.
Oh, just a bro!
-JAB (just a bro)-