The story
- Ancient Greek · derived from-ια
- Latin · derived from-ia
- Ancient Greek · derived from-κια
- Latin · derived from-cia
- Anglo-Norman · derived from-cie
- English today-cy
From Anglo-Norman -cie, ultimately from Latin -cia, -tia, Ancient Greek -κια (-kia), -τια (-tia), originally variants of Latin -ia and Ancient Greek -ια (-ia), -ία (-ía) or -εια (-eia). Original loan words like pharmacy and papacy could have formed the model.
Etymology from Wiktionary, CC BY-SA 4.0.