halothane: a nonflammable inhalation anesthetic that produces general anesthesia; used along with analgesics and muscle relaxants for many types of surgical procedures
physical entity: an entity that has physical existence
heliobacter pylori: the type species of genus Heliobacter; produces urease and is associated with several gastroduodenal diseases (including gastritis and gastric ulcers and duodenal ulcers and other peptic ulcers)