A really, really, REALLY annoying girl who tries way to hard to be popular and for some really bizarre reason becomes popular. Often a popularette has blonde hair, shiny teeth, is stupid, pops up from nowhere amongst gangs of relatively hot guys and has an annoyingly screechy voice, but there are exceptions.
Heard of "Mean Girls" the film? The two cronies who tag along with that actually popular girl, Reginor, are fine examples of popularettes.
When you aren’t the most popular person in school, but you aren’t a total loser either. You can talk to both rankings of popularity and still be liked by everyone at the same time. Plus most people know your name but not everyone.