剑桥词典the floor of a building that is at the same level as the ground outside 底层，底楼，一楼（建筑物与外面地面相平的一层） My office is on the ground floor . 我的公寓套房在底层。 例句 His office is on the ground floor .It's really dark on the ground floor .习语be/get in on the ground floor 返回 the ground floor