Open Taxi
Empty Parking Space
noun
You learned 空 means "sky," but it can also mean "empty." An empty car literally means "empty car," but in practice, you'll usually see this lit up on a taxi to mean open taxi. If you spot it, feel free to hail it down!
You might also see 空車 at a parking lot. In that case, it means there's an empty parking space available.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
あのコインパーキング、空車あるかな？
I wonder if that paid parking has an available spot.
今日はUberもLyftも中々空車がいない。
There are no available Ubers or Lyfts today.
ニューヨークでは、空車のタクシーを見たら手を上げて大声で「タクシー！」と言って下さい。
In New York, if you see an available taxi raise your hand and shout, "Taxi!"