tourniquet
noun [ C ] uk/ˈtʊə.nɪ.keɪ/ /ˈtɔː.nɪ.keɪ/ us/ˈtɝː.nɪ.kɪt/
止血带
a strip of cloth that is tied tightly around an injured arm or leg to stop it bleeding
If it continues to bleed, you may have to apply a tourniquet to the limb. 如果流血不止，你可能得在手臂上用止血带。