Apparently a primary word; a year -- year.

ἔτει (etei) − 1 Occurrence

ἔτεσιν (etesin) − 2 Occurrences

ἔτη (etē) − 29 Occurrences

ἔτος (etos) − 2 Occurrences

ἐτῶν (etōn) − 15 Occurrences