[vidarh]

The Danish belongs in the "Germanic" list; as does the Norwegian "vann" and "vatn" (the latter also Faroese, Icelandic, Norn), and Swedish "vatten".

The Romanian and French both comes from the latin aqua, just like the Italian/Spanish.

[kepler471]

Thanks for this!

Looking into it a bit more, the French is also from the latin source (aqua) - https://en.wiktionary.org/wiki/eau

[cafard]

The Welsh suggests the Ancient Greek "hudor".

[richardfontana]

That resemblance is coincidental: hudor derives from Proto-Indo-European *wed- (as does English water, wet, winter) while dwr derives from Proto-Indo-European *dʰewb- "deep" (as does English dip, deep) https://en.wiktionary.org/wiki/Reconstruction:Proto-Indo-Eur... https://www.etymonline.com/word/*wed-