bʌldʒ bʌldʒ bʌmp ɛkˈskɹɛsəns dʒʌt lʌmp pɹəʊˈtjuːbəɹəns pɹoʊˈtuːbəɹəns ˈswɛl.ɪŋ the increase in volume of certain substances when they are heated (often accompanied by release of water) something that bulges out or is protuberant or projects from its surroundings the gun in his pocket made an obvious bulge the hump of a camel he stood on the rocky prominence the occipital protuberance was well developed the bony excrescence between its horns an abnormal protuberance or localized enlargement