noun, modal particle · the uppermost story of a building, including an attic, loft, garret, or penthouse

他买下了这栋公寓的顶楼，视野非常开阔。

noun · the flat exterior surface on top of a building, often used for outdoor activities or as a garden

夏天的晚上，我们喜欢去顶楼乘凉。