JK: high-school girl

Abbreviation of 女子高生 (joshi kōsei) or abbreviation of 女子高校生 (joshi kōkōsei, “high-school girl”).

(Internet slang) Short for 常識的に考えて (jōshikiteki ni kangaete, “thinking with common sense”).

library (building)

Alternative form of 勉強

to study / to discount, to reduce the price of something

studying, studies, study

library science

librarian, library clerk