1. What does it mean?
In campus conversation, 학식 commonly shortens 학생 식당 or its meals. Online it can also refer to a university student, identifying someone by the food associated with campus life.
Also written or said as haksik
2. The nuance
The separate standard word 학식 means learning or scholarship. When used for a person, the slang can sound dismissive depending on tone; in meal plans it is usually neutral.
3. Examples
“오늘 점심은 학식 먹고 도서관 가자.”
Let's eat at the student cafeteria for lunch and then go to the library.
“학식 메뉴가 좋아서 밖에 안 나가도 되겠어.”
The campus-cafeteria menu looks good, so we won't need to go off campus.
Sources
References support the meaning and usage. Example sentences are written for NoCapWiki.