Where does “crua-ae” come from?

crua-ae (Irish) comes from Irish ae, from Middle Irish áe, from Old Irish óa, from Old Irish ó, from Proto-Celtic *au, from Proto-Indo-European h₂ew, from Proto-Indo-European ǵʰe — Postpositional intensifying particle: indeed, at any rate, in fact.

Ancestry of “crua-ae”, step by step

crua-ae traces back through two separate lines of ancestry.

via Irish ae

StepLanguageWordMeaning
1Irishaeliver; Alternative form of aoi
2Middle Irisháeliver
3Old Irishóaliver
4Old Irishófrom, of; by; since, after
5Proto-Celtic*auaway from
6Proto-Indo-Europeanh₂ewaway from, off; again
7Proto-Indo-EuropeanǵʰePostpositional intensifying particle: indeed, at any rate, in fact

via Irish crua

StepLanguageWordMeaning
1Irishcruahard, firm; difficult; severe
2Middle Irishcrúaide
3Old Irish-eForms concrete or abstract nouns from adjectives
4Old Irishlánfull
5Proto-Celticɸlānosfull
6Proto-Indo-Europeanpl̥h₁nósfull
7Proto-Indo-Europeanpleh₁-to fill
Every word from Proto-Indo-European ǵʰe