any device for compressing a blood vessel to stop bleeding or control the circulation of blood to some part, as a bandage twisted about a limb and released at intervals or a pad pressed down by a screw
See tourniquet in American Heritage Dictionary 4
(to͝orˈnĭ-kĭt, tûrˈ-)
noun
A device, typically a tightly encircling bandage, used to check bleeding by temporarily stopping the flow of blood through a large artery in a limb.