The word "凸出" is formed by combining the pictographic character "凸", which visually represents a convex or protruding shape, with the ideographic character "出", which depicts movement outward, such as exiting from an enclosure. In this compound, "凸" contributes the meaning of a bulging or raised state, while "出" reinforces the action of extending or projecting outward, together creating the meaning "to protrude" or "to stick out".