剑桥词典the floor of a building that is at the same level as the ground outside 底層，底樓，一樓（建築物與外麪地麪相平的一層） My office is on the ground floor . 我的公寓套房在底層。 例句 His office is on the ground floor .It's really dark on the ground floor .習語be/get in on the ground floor 返回 the ground floor