Where does “Vadul lui Isac” come from?

Vadul lui Isac (Romanian) comes from Romanian lui, from Latin illūi, from Latin illī, from Latin ille, from Latin olle, from Proto-Italic *olnos — that.

Ancestry of “Vadul lui Isac”, step by step

Vadul lui Isac traces back through two separate lines of ancestry.

via Romanian lui

Step	Language	Word	Meaning
1	Romanian	lui	his; to him
2	Latin	illūi	him dative singular masculine; apparently also genitive
3	Latin	illī	found in
4	Latin	ille	that; those; "; demonstrative pronoun "; that...
5	Latin	olle	Archaic form of ille
6	Proto-Italic	*olnos	that

via Romanian vad

Step	Language	Word	Meaning
1	Romanian	vad	ford
2	Latin	vadum	A shallow, ford, shoal; A body of water; sea,...
3	Proto-Italic	waðom	ford, shallow water
4	Proto-Indo-European	wadʰom	—

Every word from Proto-Italic *olnos →Every word from Latin olle →Every word from Latin ille →