A person more or less into educating himself. Most students attend some kind of school. In CoC it is mostly a College or a University. The University can be either an excuse for an intense social life or a place that gives the character an opportunity to dig deep into books he or she otherwise wouldn't get their hands on.
Many educational institutions have many deeply buried secrets. This can be something bad that happened in the lecturing hall or on the campus....it could also be scientific studies that for some reason or an other has been shut down. A snooping student may wake up something others have tried to put to sleep.