Where does “ἑπταετηρίς” come from?

ἑπταετηρίς (Ancient Greek) comes from Ancient Greek ἔτος, from Ancient Greek ϝέτος, from Proto-Indo-European wétos, from Proto-Indo-European wet- — year; year-old.

ἑπταετηρίς (Ancient Greek): septennium

Definitions

septennium

Ancestry of “ἑπταετηρίς”, step by step

ἑπταετηρίς traces back through two separate lines of ancestry.

via Ancient Greek ἔτος

Step	Language	Word	Meaning
1	Ancient Greek	ἔτος	year
2	Ancient Greek	ϝέτος	—
3	Proto-Indo-European	wétos	year
4	Proto-Indo-European	wet-	year; year-old

via Ancient Greek ἑπτά

Step	Language	Word	Meaning
1	Ancient Greek	ἑπτά	seven
2	Proto-Hellenic	heptə́	seven
3	Proto-Indo-European	septḿ̥	seven

Every word from Proto-Indo-European wet- →Every word from Proto-Indo-European wétos →Every word from Ancient Greek ϝέτος →