Which medical term describes a blood clot in the leg?

The term that specifically refers to a blood clot forming in a deep vein, most commonly in the leg, is deep vein thrombosis. This condition occurs when a thrombus, or clot, develops within the venous system, impairing blood flow and potentially leading to complications such as pulmonary embolism if part of the clot dislodges and travels to the lungs.

Phlebitis refers to the inflammation of a vein, which may or may not be associated with a clot, but it does not specifically denote the presence of a clot itself. Peripheral vascular disease is a broader term describing diseases of blood vessels outside of the heart and brain, and while it can involve blood flow issues, it is not specifically referring to a clot in the leg. Varicose veins indicate swollen and twisted veins that are often visible under the skin and result from valve dysfunction, but do not explicitly mean a clot is present. Thus, deep vein thrombosis is the most accurate description for a blood clot in the leg.