A term started down in Connecticut by a wise man. Noone has the exact original meaning but lets just say it was a word used for an annoying girl or perhaps one that you just didnt find attractive. The phrase has since developed into any female that you see on the street and if your buddies are cool with it you can even refer to their girlfriends or fiances as baggas! Random ladies love it when you call them baggas so the spread the phrase.
Hey look at that bagga over there I bet Frany would love her.