Where does “críochnú” come from?

críochnú (Irish) comes from Irish -ú, from Old Irish -ugud, from Old Irish -ad, from Proto-Celtic -tus, from Proto-Indo-European -tus — Derives action nouns from verb roots.

Ancestry of “críochnú”, step by step

StepLanguageWordMeaning
1Irish-úRegular verbal noun of second-conjugation verbs,...
2Old Irish-ugud—
3Old Irish-adsuffix forming verbal nouns; suffix forming the...
4Proto-Celtic-tusForms action nouns from verb stems
5Proto-Indo-European-tusDerives action nouns from verb roots
Every word from Proto-Indo-European -tus →Every word from Irish -ú →Every word from Old Irish -ad →