Where does “(av)unclus” come from?

(av)unclus (Vulgar Latin) comes from Latin avunculus, from Proto-Indo-European h₂éwh₂os — maternal grandfather; maternal uncle.

Ancestry of “(av)unclus”, step by step

Step	Language	Word	Meaning
1	Latin	avunculus	maternal uncle, mother's brother; mother's...
2	Proto-Indo-European	h₂éwh₂os	maternal grandfather; maternal uncle

(av)unclus — Etymology, Origin & Word History | Etymology Explorer