Where does “ελληνικά” come from?

ελληνικά (Greek) comes from Greek ελληνικός, from Ancient Greek Ἑλληνῐκός.

ελληνικά (Greek): Greek; Nominative, accusative and...

Definitions

Step	Language	Word	Meaning
1	Greek	ελληνικός	Greek
2	Ancient Greek	Ἑλληνῐκός	—

ελληνικά — Etymology, Origin & Word History | Etymology Explorer