Warfarin has 3 different meanings across 1 category:
Noun
an anticoagulant (trade name Coumadin) use to prevent and treat a thrombus or embolus
A coumarin salt, warfarin sodium, found in certain clovers, that retards blood coagulation:
Manufactured as a pharmaceutical drug and used in low dosage, with regular monitoring, for the prevention of thrombosis and embolism.