Where does “madfallod dŵr” come from?

madfallod dŵr (Welsh) comes from Welsh madfall ddŵr, from Welsh madfall, from Welsh mabddall, from Welsh mab, from Old Welsh map, from Proto-Brythonic mab, from Proto-Celtic makʷos, from Proto-Indo-European mh₂ḱwos — to raise, increase; long.

Ancestry of “madfallod dŵr”, step by step

StepLanguageWordMeaning
1Welshmadfall ddŵrnewt
2Welshmadfalllizard; slowworm, blindworm; newt
3Welshmabddallperson who is born blind; blindworm, slowworm;...
4Welshmabboy, son, infant, child of either sex, minor, youth
5Old Welshmapson
6Proto-Brythonicmabson
7Proto-Celticmakʷosson
8Proto-Indo-Europeanmh₂ḱwos
9Proto-Indo-Europeanmeh₂ḱ-to raise, increase; long
Every word from Proto-Indo-European meh₂ḱ-