Heparin (noun)

1. A substance that is used as an anticoagulant (a blood thinner) to prevent the formation of blood clots and to treat conditions such as deep vein thrombosis and pulmonary embolism.
2. A natural polysaccharide that is used as a anticoagulant in medical treatments.

Origin:

The word "heparin" is derived from the greek word "hepar" which means "liver" as it was first extracted from the liver of cows and hogs.

Examples:

1. Patients receiving heparin have to have their blood monitored regularly.
2. The patient was started on heparin to prevent blood clots.
3. Heparin is used in dialysis to prevent clotting in the extracorporeal circuit.