下山
xiàshān · HSK 7
to go down a hill; (of the sun or moon) to set
⛰️ 下山 = 下 (down) + 山 (mountain) = go down the mountain
下 — horizontal line 一 + mark below
下 is an indicative character: a long horizontal line represents a reference level, and a shorter stroke placed beneath it points to the area below. The original meaning 'below, down' comes directly from this spatial diagram, and it later extended to verbs like 'descend' and 'lower'.
山 — pictograph of three mountain peaks
山 is one of the oldest pictographs in Chinese, originally drawn in oracle bone script as three pointed peaks rising from a baseline. The form was simplified over time into the modern three vertical strokes on a base. Its meaning has stayed remarkably stable: 'mountain' or 'hill'.