noun
box and cover; container and lid
A rare literary or technical term referring to a box together with its lid, or metaphorically to things that fit together perfectly. Not used in everyday conversation.
「函蓋相称」という四字熟語で、函と蓋がぴったり合うように、物事がうまく調和することを表す。
The four-character idiom 函蓋相称 expresses that things harmonize well, just as a box and its lid fit perfectly together.