The word 入口 is formed by combining two pictographic characters into a direct, conceptual compound. The first character, 入, pictorially represents "to enter" (resembling the pointed tip of an object going into something). The second, 口, is a pictogram of a "mouth" or an "opening". When placed together, their literal meanings merge visually and conceptually to create the idea of "an opening for entering", hence, an entrance, doorway, or point of entry.