The story
- Proto-Indo-European*ḱerd-
- Proto-Indo-European*ḱḗr
- Proto-Indo-European*ḱr̥díyeh₂
- Proto-Hellenic*kərdíyā
- Ancient Greekκᾰρδῐ́ᾱ (kărdĭ́ā)
- Ancient Greekκᾰρδῐᾰκός (kărdĭăkós)
- Latincardiacus
- Middle Frenchcardiaque
- English todaycardiac
From Middle French cardiaque, from Latin cardiacus, from Ancient Greek καρδιακός (kardiakós, “relating to the heart”), from καρδία (kardía, “heart”); by surface analysis, cardi- + -ac.
Etymology from Wiktionary, CC BY-SA 4.0.