The word 外表 is formed by combining two characters, each contributing a core meaning to create a new, unified concept. The first character, 外 (wài), means "outside" or "external", establishing the realm. The second, 表 (biǎo), means "surface" or "to manifest", specifying the visible aspect. When placed together, they logically and visually combine to express the idea of an "external surface" or "outward appearance", where 外 defines the location and 表 defines the nature of what is seen.