ἥν

From LSJ

μέτρον γὰρ τοῦ βίου τὸ καλόν, οὐ τὸ τοῦ χρόνου μῆκος → for life's measure is its beauty not its length (Plutarch, Consolatio ad Apollonium 111.D.4)

Source

French (Bailly abrégé)

acc. sg. fém. de ὅς, ἥ, ὅ;
poét. p. ἑήν, acc. sg. fém. de ἑός.

Greek Monotonic

ἥν: αιτ. ενικ. θηλ. της αναφορ. αντων. ὅς και της κτητ. αντων. ὅς, ἑός.

Russian (Dvoretsky)

ἥν:
I acc. sing. к ἥ (f к ὅς).
ἥν: II поэт. (= ἑήν) acc. sing. к ἑός.