Dome is from French dôme or Italian duomo ('cathedral, dome'), from Latin domus ('house'), itself from Greek doma ('house, roof'). The ancestry passes through French dôme, Latin domus, and Proto-Indo-European *dem-. In present use as noun and verb, it means "a rounded vault forming the roof of a building or structure", keeping the historical formation close to the word's ordinary semantic work. Related words include domical; derived forms include domed and doming. The surrounding word family keeps the same base visible in domed, doming, and domical, showing how the headword belongs to a larger cluster rather than standing alone.