LuAnn, who I actually became quite close to during filming never asked me what "holla" meant. Even after defining me as "gangsta chic," and I can only ascertain that she decided to "save it" for the couch. So, for LuAnn and for anyone else out there who does not already know, below please find a quick cheat sheet on the uses and definitions for how or why one can use "holla!"
Origin: "holla" is a common colloquial spelling/pronunciation of holler.
Holla as an interjection: a greeting. "Holla!"
Exclamation of celebration. "I got $257 in tips from last night. Holla!"
Holla as a verb: to talk to or to contact at some later time. "I'll holla at you later."
When trying to talk to or attract a member of the opposite sex; "hit on." "Every time I go to the mall, those fools be tryin' to holla." Or "Can I holla at you baby?"
To contact someone, e.g. via a telephone call, e-mail, cell phone text message, etc. Also holla back. Typically used as a request. "I'll see ya later. Holla!" OR Message left on an answering machine: "Well, I guess you're not home. Holla back at me when you get in!"
"Holla" can also be used as a goodbye, a request to contact someone. So "Holla," as goodbye means roughly, "Contact me later." "I'm leaving man. Holla."