first floorBrE/ˌfɜːst ˈflɔː(r)/NAmE/ˌfɜːrst ˈflɔːr/ (usuallythe first floor) noun[sing.](BrE) thelevelofabuildingabovethegroundlevel底层以上的一层；二楼◆Menswearisonthefirstfloor. 男装在第二层。(NAmE) (BrEˌground ˈfloor) thefloorofabuildingthatisatthesamelevelasthegroundoutside底层，底楼，一楼（建筑物与外面地面相平的一层）▸first-floorBrE/ˌfɜːst ˈflɔː(r)/NAmE/ˌfɜːrst ˈflɔːr/adjective[only before noun]◆afirst-floorflat/apartment二楼的一套公寓floor
In BrE the floor of a building at street level is the ground floor, the one above it is the first floor and the one below it is the basement, or lower ground floor in a public building.在英式英语中，地面的楼层叫 ground floor，上面一层叫 first floor，下面一层叫 basement 或在公共建筑中叫 lower ground floor。
In NAmE the floor at street level is usually called the first floor, the one above it is the second floor and the one below it is the basement. In public buildings the floor at street level can also be called the ground floor.在美式英语中，地面的一层通常叫 first floor，上面一层叫 second floor，下面一层叫 basement。在公共建筑中，地面的一层亦可称为 ground floor。