car·di·o·lip·in 
(kär′dē-ō-lĭpĭn)
(kär′dē-ō-lĭpĭn)n.
A phospholipid usually obtained from beef heart, used in combination with phosphatidylcholine and cholesterol as an antigen to diagnose syphilis.
[CARDIO- + lipin, lipid (Greek lipos, fat; see LIPO- + -IN).]