楼下
loú xià · HSK 1
downstairs
🏢⬇️ 楼下 = building + below; the floor beneath where you are
楼 means multi-story building, 下 means below or under. Together they literally mean below-the-building-level, i.e. the floor downstairs. Contrast with 楼上 (building + above) = upstairs.
楼 — wood radical 木 + 婁 (lóu, phonetic)
楼 is a phono-semantic compound. The 木 radical signals wood, fitting a multi-storied wooden building, while 婁 supplies the lóu sound. Originally written 樓, it referred to a tower or upper story, and today means a multi-floor building or a specific floor.
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'.