the ground floor

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