The story
- Proto-Indo-European*ḱerd-
- Proto-Indo-European*ḱḗr
- Proto-Indo-European*ḱr̥díyeh₂
- Proto-Hellenic*kərdíyā
- Ancient Greekκαρδία (kardía)
- Englishcardio-
- Medieval Latinprōtēctīvus
- Englishprotective
- English todaycardioprotective
From cardio- + protective.
Etymology from Wiktionary, CC BY-SA 4.0.