mindmap root((突出)) projection implies a jutting out especially at a sharp angle: those ~s along the wall are safety hazards. protrusion suggests a thrusting out so that the extension seems an excrescence or a deformity: the bizarre ~s of a coral reef. protuberance implies a growing or swelling out from a surface in rounded form: a skin disease marked by warty ~s. bulge suggests an expansion or swelling of a surface caused by pressure withion or below: ~s soon appeared in the tile floor.