The word 壁炉 (bìlú, meaning "fireplace") is formed through direct, conceptual combination: the first character 壁 means "wall", and the second character 炉 means "stove" or "hearth". It literally describes a "wall-stove", creating a clear mental image of a heating appliance that is structurally set into or against a wall, distinguishing it from a freestanding stove or an open pit.