Where does “Etna” come from?

Etna comes from Irish Eithne, which derives from Ancient Greek Αἴτνη, a word of unknown ultimate origin.

Ancestry of “Etna”, step by step

Step	Language	Word	Meaning
1	Italian	Etna	—
2	Latin	Aetna	—
3	Ancient Greek	αἴθω	To ignite, kindle, light; To burn, blaze
4	Proto-Hellenic	*áitʰō	—

Etna — Etymology, Origin & Word History | Etymology Explorer