실학이 · 실학을
Silhak, the Practical Learning movement (late Joseon)
Example
정약용은 실학을 크게 발전시킨 학자예요.
Jeong Yak-yong is a scholar who greatly developed Practical Learning.
Word parts
실 real+학 study
Literally 'real learning' — scholarship aimed at practical problems, not abstract theory.