By contradistinction, the Italian word for a cathedral sensu stricto is cattedrale.
Similar words exist in other European languages: Dom (German and Dutch), dom (Romanian), dóm (Hungarian and Slovak), dôme (French - usually less common), domo (Portuguese), doms (Latvian), tum (Polish), domkirke (Danish and Norwegian), dómkirkja (Icelandic), domkyrka (Swedish), toomkirik (Estonian), tuomiokirkko (Finnish) and so on.
Also in these languages the respective terms do not necessarily refer to a church functioning as a cathedral, but also to proto-cathedrals or simply prominent church buildings, which have never been a cathedral in the exact sense of that word.
German Dom and Polish tum became the synecdoche used – pars pro toto – for most existing or former collegiate churches.
According to the Oxford English Dictionary and the Zingarelli, the word duomo derives from the Latin word domus, meaning "house", as a cathedral is the "house of God", or domus Dei.