参議院
さんぎいん · sangiin · JLPT N1 · noun
House of Councilors
院 — left ear 阝(阜) + complete 完
院 is a semantic-phonetic compound. The left 阝 (from 阜, mound/hill) suggests walls or enclosed terrain, hinting at an enclosed space. The right 完 (wán) provides the sound and originally meant 'complete', so 院 came to mean a walled courtyard or institution like a hospital or academy.