the first floor AmEthe floor of a building at the bottom level一楼，底层:•Fire broke out on the first floor of the apartment building.公寓楼的底层起火。the first floor BrEthe floor of a building just above the one at the bottom level二楼〔指底层上面的楼层〕;⇒ground floor:•a flat on the first floor二楼的一套公寓 |