roof
[ru:f]
n.
屋顶, 房顶, 顶
1.The exterior surface and its supporting structures on the top of a building.
屋盖，屋顶构架：建筑物顶部的外表面及其支撑结构回
2.The upper exterior surface of a dwelling as a symbol of the home itself:
房屋，住处：作为家答的象征的住宅的外表面上部
3.The top covering of something:
顶，顶部：某物的顶层覆盖物：
the roof of a car.
车顶
天花板是ceiling,这词更偏向于室内的.