1) To fight or argue with someone.
2) A video game based in the future, where you live in 'Vaults' and you try to escape to the polluted world outside (nuclear bomb war)
1) Jenny: I wish you'd shut up! *pushes*
Carl: *slaps*
Jenny: I'm going to fall out with you.
2) Ryan: Hey, have you seen that new video gameFallout 3? It's awesome dude.
of military origin esp. U.S. Army...
1. to break ranks
2. to step out of formation 3. to be left behind because your fat ass cant keep up
4. to anounce ones exit
5. to quit drinking. vomit, or pass-out
private partz fall out
im gonna fall-out
dont fall out you fat fuck or im gonna PT you to death!
Jones fell out and puked all over the cab