warfarin

noun

war·​fa·​rin ˈwȯr-fə-rən 

: a crystalline anticoagulant coumarin derivative C₁₉H₁₆O₄ that inhibits the production of prothrombin by vitamin K and is used as a rodent poison and in medicine

also : its sodium salt C₁₉H₁₅NaO₄ used especially in the prevention or treatment of thromboembolic disease

Examples of warfarin in a Sentence

Recent Examples on the Web

When clots are in the lungs, patients often need medications called blood thinners, such as heparin or warfarin, to help the body dissolve them. — Jen Christensen, CNN Money, 20 Oct. 2026

CoQ10 may also interact with certain medications, including warfarin and statins, so check with a healthcare provider like your pharmacist before taking it. — Sara Hoffman, Verywell Health, 16 Oct. 2026

There's conflicting research about whether cranberry interacts with the blood thinner Coumadin (warfarin). — Cynthia Sass, Health, 27 Apr. 2026

For those on blood thinners like warfarin, taking noni with your medication can also reduce your body’s blood-clotting ability. — Bestreviews, Mercury News, 10 Feb. 2026

Word History

Etymology

Wisconsin Alumni Research Foundation (its patentee) + coumarin

First Known Use

1950, in the meaning defined above

Medical Definition

warfarin

noun

war·​fa·​rin ˈwȯr-fə-rən 

: a crystalline anticoagulant coumarin derivative C₁₉H₁₆O₄ related to dicumarol that inhibits the production of prothrombin by vitamin K and is used as a rodent poison and in medicine

also : its sodium salt C₁₉H₁₅NaO₄ used especially in the prevention or treatment of thromboembolic disease see coumadin