The word 剩下 is formed through the complementary combination of its two component characters: 剩, which carries the core meaning of "surplus" or "what remains", and 下, which here functions not as "down" but as a directional or resultative complement indicating a state of settlement or being left behind. Thus, the formation visually and conceptually depicts an action or process where, after other elements are removed or used, a residual portion settles or is left over in place, merging the idea of remainder (剩) with the resulting state of being left (下).