Similar to being a transvestite or a poser, a Lesbianite is the product of a straight girl pretending to be a lesbian. This is usually temporary and last for one night but can sometimes be for an extended period of time, especially when she's whoring herself out for attention and/or money, drugs are also a possibility.
EX 1.) Did you hear about Gynette's vice of being a lesbianite? She totally whored herself out for more college money and beer last night at that drag party, what a slut.
EX 2.) Girl 1. "Dude, I totally need more drugs and I don't have any money."
Girl 2. "Hey, Lady. Lets become Lesbianites and make some hard cash tonight at the drag party."
Girl 1. "Yeah, LESBIANITES UNITE!"