anticoagulant

noun

chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time
chemicals used to stop blood clotting in laboratory blood tests

Wiktionary

adj

Etymology: Etymology tree Proto-Indo-European *h₂ent- Proto-Indo-European *-s Proto-Indo-European *h₂énts Proto-Indo-European *-i Proto-Indo-European *h₂énti Ancient Greek ᾰ̓ντῐ́ (ăntĭ́) Ancient Greek ἀντι- (anti-)der. English anti- English coagulant English anticoagulant From anti- + coagulant.

That prevents coagulation, that stops blood from clotting.
“The posologies employed require careful clinical and electrical supervision, and the same anticoagulant measures as for electrical cardioversion are necessary.”

noun

A substance that prevents coagulation (stops blood from clotting); especially, any of a group of pharmaceutical drugs that reduce the clotting speed or affinity of the blood by any of several mechanisms (e.g., inhibiting platelet function, inhibiting clotting factor (protein) production or function, increasing antithrombin function).
“If you are taking an anticoagulant (blood-thinning medication ) and have been given a new prescription for Equagesic, be sure that your doctor is aware that there is Aspirin in Equagesic.”
“In the case of pathological hypercoagulative conditions such as thrombosis and embolism, 4-hydroxycoumarin based oral anticoagulants, including warfarin as a well-known example, are administered to block the enzymatic function of VKORC1, effectively diminishing turnover of the vitamin K cycle.”