Where does “ουδέτερος” come from?

ουδέτερος (Greek) comes from Ancient Greek οὐδέτερος, from Ancient Greek οὐδέ, from Ancient Greek οὐ, from Ancient Greek οὐκί, from Proto-Hellenic oyuki, from Proto-Indo-European (ne) h₂óyu kʷid — ever, on your life; not ever, not on your life.

ουδέτερος (Greek): neuter, sexless; neutral, non-aligned; the...