Where does “Iltuden” come from?

Iltuden (Breton) comes from Breton eñ, from Proto-Celtic em.

Ancestry of “Iltuden”, step by step

Iltuden traces back through two separate lines of ancestry.

via Breton eñ

Step	Language	Word	Meaning
1	Breton	eñ	he, him
2	Proto-Celtic	em	—

via Breton Iltud

Step	Language	Word	Meaning
1	Breton	Iltud	—
2	Old Breton	tut	—

Every word from Proto-Celtic em →Every word from Breton eñ →