外科
げか · geka · JLPT N2 · noun
department
🏥 外 (outside) + 科 (department): the department for operations on the body
外 also means external or outside. Surgery treats conditions by operating on the body, so 外科 is the outside-treatment department. Its counterpart is 内科 (naika), internal medicine.
外 — evening 夕 + divination 卜
Originally a compound of 夕 (evening) and 卜 (divination). Ancient Chinese divinations were performed in the morning; doing them at evening (夕) was considered irregular or 'outside' the norm. From this sense of deviation, 外 came to mean 'outside' or 'external'.
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.