car ‧ di ‧ ac /ˈkɑːdi-æk $ ˈkɑːr-/ BrE AmE adjective [only before noun] medical
[ Date: 1600-1700 ; Language: Latin ; Origin: cardiacus , from Greek , from kardia ; ⇨ ↑ cardio- ]
relating to the heart:
cardiac surgery
cardiac arrest/failure (=when the heart stops working)