protuberance

projection, protrusion, protuberance, bulge mean an extension beyond the normal line or surface. projection implies a jutting out especially at a sharp angle <those projections along the wall are safety hazards>. protrusion suggests a thrusting out so that the extension seems a deformity <the bizarre protrusions of a coral reef>. protuberance implies a growing or swelling out in rounded form <a skin disease marked by warty protuberances>. bulge suggests an expansion caused by internal pressure <bulges in the tile floor>.