Where does “ku” come from?

ku (Middle Welsh) comes from Proto-Brythonic kʉβ̃, from Proto-Celtic koimos, from Proto-Indo-European ḱóymos, from Proto-Indo-European ḱey- — to be lying down; to settle.

Ancestry of “ku”, step by step

StepLanguageWordMeaning
1Proto-Brythonickʉβ̃dear, nice
2Proto-Celtickoimosdear, nice
3Proto-Indo-Europeanḱóymosof the home, belonging to the family; village,...
4Proto-Indo-Europeanḱey-to be lying down; to settle

Words derived from “ku

Every word from Proto-Indo-European ḱey-Every word from Proto-Indo-European ḱóymosEvery word from Proto-Celtic koimos