Stupid bitches (usually hot) who think they own the world. Usually very rich and stuck up. They call other people sluts, when in reality they hook up with 5 ppl (3 boys 2 girls) at parties while drunk and end up smoking. Even though they are hot, who would honestly put up with stupid bitches like that? They also think they look fashionable, and they usually do, but clothes can't hide what's on the indside.
Damn, that preppy girl is fine! But what the fuck, is she drunk? An oh man, what is she doing to that dumb senior over there? Shit! She's only a freshman and she's goin down on him!
Another example is the stuck up bitch who wrote the second definition on this page. The one who said "People tear preps down so they feel better about their fashion statements" and "Oh we're so sterotyped." That dumbass is a prppy girl.