The story
- Proto-Indo-European*sper-
- Proto-Indo-European*spérmn̥
- Proto-Hellenic*spérmə
- Ancient Greekσπέρμα (spérma)
- Proto-Indo-European*h₃ed-
- Proto-Indo-European*h₃édosder.?
- English today-spermous
From Ancient Greek -σπερμος (-spermos) [itself from σπέρμα (spérma) + -ος (-os)] (as used, for example, in ἄσπερμος (áspermos)) + -ous.
Etymology from Wiktionary, CC BY-SA 4.0.