Where does “-adh” come from?

-adh (Scottish Gaelic) comes from Old Irish -ad, from Proto-Celtic -tus, from Proto-Indo-European -tus — Derives action nouns from verb roots.

Ancestry of “-adh”, step by step

StepLanguageWordMeaning
1Old Irish-adsuffix forming verbal nouns; suffix forming the...
2Proto-Celtic-tusForms action nouns from verb stems
3Proto-Indo-European-tusDerives action nouns from verb roots

Words derived from “-adh”

Every word from Proto-Indo-European -tus →Every word from Old Irish -ad →Every word from Proto-Celtic -tus →