Where does “Δῃάνειρα” come from?

Δῃάνειρα (Ancient Greek) comes from Ancient Greek ἀνήρ, from Proto-Hellenic *anḗr.

Ancestry of “Δῃάνειρα”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ἀνήρ	man; husband; human being, as opposed to a god
2	Proto-Hellenic	*anḗr	—

Δῃάνειρα — Etymology, Origin & Word History | Etymology Explorer