Where does “Αυνάν” come from?

Αυνάν (Greek) comes from Ancient Greek Αὐνάν, from Hebrew אונן — to masturbate; masturbator.

Αυνάν (Greek): Onan son of Judah who is known for having ejaculated on the floor instead of during intercourse with Tamar, to prevent her bearing a child which would legally have been his deceased brother's