科目
kēmù · HSK 7
school subject
📚 科目 = 科 category/branch + 目 item/heading = a heading-by-category, i.e. a subject
科 is a branch or category (as in 科学 science); 目 is an item or heading (as in 目录 table of contents). Stack them and you get categorized headings: the school subjects and ledger account lines that 科目 names.
科 — grain 禾 + measure 斗
科 combines 禾 (grain) and 斗 (a dipper/measure), originally depicting the act of measuring or grading grain. From this, it extended to mean classification, category, and branch of study. Today it commonly appears in words for science (科学) and academic disciplines.