Proto-Celtic *dubros

→ English Zurich (derived)

→ English Dover (derived)

→ English Thames (cognate)

→ English Douro (mention)

→ Breton dour (inherited)

→ Welsh dŵr (inherited)

→ Welsh Frwdwr (derived)

→ Spanish Duero (derived)

→ Irish dobhar (inherited)

→ Galician Val do Dubra (derived)

→ Galician Dubra (derived)

→ Cornish dowr (inherited)

→ Latin Tiberis (mention)

→ Latin Durius (derived)

→ Latin Dubris (derived)

→ Latin Duranius (derived)

→ Latin Dabrona (derived)

→ Latin Taurini (derived)

→ Dutch Duffel (derived)

→ Portuguese Douro (derived)

→ Old Irish dobur (inherited)

→ Middle Welsh dwfyr (inherited)