vacant land; empty lot; unoccupied ground
Refers to a piece of land that is not currently built on or used, often in an urban or suburban context.
There is a large vacant lot near the station.
That empty lot is used as a parking lot.
There is a vacant lot near the station.
There is a plan to make use of that vacant lot to build a park.
I heard they're going to build a new house on the vacant lot.
空地 simply means unused land in general, whereas 遊休地 specifically refers to land or facilities that are idle despite being intended for productive use.
空地 refers to vacant outdoor land, while 空室 refers to an unoccupied room or apartment, so the two should not be confused despite both starting with 空.
Compound of 空 (くう, 'empty, sky') + 地 (ち, 'land, ground'). The reading くうち is a straightforward on'yomi combination.