the second floor
noun [ S ] uk/ˌsek.ənd ˈflɔːr/ us/ˌsek.ənd ˈflɔːr/
(英国英语中的)三楼;(美国英语中的)二楼
in British English, the floor of a building that is two floors above ground level, or in American English, the floor that is directly above ground level
I live on the second floor. 我住在三楼。