1. What does it mean?
과탑 combines 과, academic department, with top. It usually refers to the student with the highest grades in the relevant department or cohort, and can be used informally to praise exceptional academic performance.
Also written or said as gwatap
2. The nuance
The comparison group and period matter: a semester's top student is not necessarily first across every year. It is a nickname or description, not a universal official title.
3. Examples
“이번 학기 과탑인 친구가 공부 방법을 알려 줬어.”
The friend who topped our department this semester shared their study method.
“과탑이라고 모든 과목이 쉬운 건 아니래.”
They say even the top student doesn't find every subject easy.
Sources
References support the meaning and usage. Example sentences are written for NoCapWiki.