The kind of
student that blends in with the
student body. They may take the average courses, like
psychology, and usually at least one
extracurricular activity, assuming they're in
vogue on your campus. Your typical average
schoolkid.
The real definition, at least my self-definition, is a student who works as hard as everyone else, no more, no less. Meaning if I'm in a class full of slackers, it's very difficult not to do the same. Inversely, if I surround myself with honors physics students, I find it much easier to study for extended periods of time and work much harder in general, because I have to put in more than average effort to keep up.
It's the student mentality of not trying to be that competitive, gunning for the upper academic percentage of the class, meaning you'll study harder than the 'slackers' and find the motivation to try to go the extra distance if possible.
This kind of attitude makes it difficult to pick a college. You want one that's competitive to your abilities, so you can learn things and not slack off. OTOH, you don't want a cutthroat academic college that puts impossible demands on you, like Swarthmore.