The Collaborative International Dictionary of English v.0.48:

Tourniquet \Tour"ni*quet\, n. [F., fr. tourner to turn.] (Surg.)
   An instrument for arresting hemorrhage. It consists
   essentially of a pad or compress upon which pressure is made
   by a band which is tightened by a screw or other means.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tourniquet
    n 1: bandage that stops the flow of blood from an artery by
         applying pressure [syn: compression bandage,
         tourniquet]

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "tourniquet":
   Ace bandage, Band-Aid, adhesive tape, application, band, bandage,
   bandaging, binder, brace, cast, cataplasm, compress, cotton,
   court plaster, cravat, dressing, elastic bandage, epithem,
   four-tailed bandage, gauze, lint, plaster, plaster cast, pledget,
   poultice, roller, roller bandage, rubber bandage, sling, splint,
   sponge, stupe, tampon, tape, tent, triangular bandage