The word 下面 is formed by combining two pictographic and conceptual characters. The first character, 下, is a simple ideogram depicting one thing (a short stroke) positioned below a line, directly representing the idea of "under" or "below". It is combined with 面, a character whose earliest form schematically represented a face, which broadened in meaning to signify "surface", "side", or "aspect". Therefore, 下面 is a logical compound where the concept of "below" (下) is applied to the concept of a "surface" or "side" (面), visually and conceptually synthesizing to mean "the lower side" or "the underside".