약학이 · 약학을
pharmacy (field of study), pharmacology
Example
언니는 대학교에서 약학을 전공하고 있어요.
My older sister is majoring in pharmacy at university.
Word parts
약 medicine+학 study
Literally 'medicine studies'. -학 = field of study: 의학, 경제학.
Good to know
Pronounced [야칵]; 약학 is the field of study, while 약국 is the drugstore.