Where does “Kilian” come from?

Kilian (German) comes from Irish Cillian, from Irish ceallach, from Irish -ach, from Middle Irish -ach, from Old Irish -ach, from Proto-Celtic -ākos, from Proto-Indo-European -eh₂ḱos, from Proto-Indo-European -kos — Creates deadjectival and desubstantival...

Ancestry of “Kilian”, step by step

StepLanguageWordMeaning
1IrishCillian
2Irishceallachrecluse, hermit; celled, cellular
3Irish-achForms nouns from other nouns and adjectives with...
4Middle Irish-achForms adjectives meaning "related to, having,...
5Old Irish-achForms adjectives meaning "related to, having,...
6Proto-Celtic-ākosForms adjectives from nouns and adjectives with...
7Proto-Indo-European-eh₂ḱos
8Proto-Indo-European-kosCreates deadjectival and desubstantival...
Every word from Proto-Indo-European -kosEvery word from Irish -achEvery word from Old Irish -ach