空 (kōng) as a noun refers to empty or open space. It often appears as a modifier in compound words such as 空地 (open ground or clearing). It conveys the idea of vacancy or openness in a physical area.
村子后面有一块很大的空地。
cūnzi hòumiàn yǒu yī kuài hěn dà de kòngdì.
Behind the village there is a large open space.
公园里有一片空地,适合孩子们玩耍。
gōngyuán lǐ yǒu yī piàn kòngdì, shìhé háizimen wánshuǎ.
There is an open space in the park, suitable for children to play.
我们在空地上搭了一个帐篷。
wǒmen zài kòngdì shàng dā le yī gè zhàngpéng.
We set up a tent on the open ground.