a. on or of lower floors of a buildingr. on a floor below
n. 楼下a. 楼下的adv. 在楼下
1. I will be downstairs in a few minutes.
我几分钟后会在楼下。
2. The children are playing downstairs.
孩子们在楼下玩。
3. Please bring me a glass of water from downstairs.
请从楼下给我拿一杯水。