Where does “Cumulus-Wolke” come from?

Cumulus-Wolke (German) comes from German wolke, from Middle High German wolken, from Old High German wolkan, from Proto-Germanic wulkaną, from Proto-Indo-European welg- — wet, damp.

Ancestry of “Cumulus-Wolke”, step by step

Cumulus-Wolke traces back through two separate lines of ancestry.

via German wolke

StepLanguageWordMeaning
1Germanwolkecloud, made of steam, ash, smoke or anything that resembles such a mass (may also be Schwaden or Schwade in this sense)
2Middle High Germanwolkencloud
3Old High Germanwolkan—
4Proto-Germanicwulkanącloud
5Proto-Indo-Europeanwelg-wet, damp

via German Cumulus

StepLanguageWordMeaning
1GermanCumuluscumulus
2Latincumulusheap, pile; surplus; summit
3Proto-Indo-Europeanku-m-olo—
4Proto-Indo-Europeanḱewh₁-to swell; to be strong
Every word from Proto-Indo-European welg- →Every word from Proto-Germanic wulkaną →Every word from Old High German wolkan →