ἠθική (Ancient Greek) comes from Ancient Greek ἠθικός, from Ancient Greek ἦθος, from Ancient Greek ἔθος, from Proto-Indo-European swe-dʰh₁-, from Proto-Indo-European dʰeh₁- — to do, put, place.
ἠθική (Ancient Greek): feminine nominative/vocative singular of ἠθικός