It was a blue sky without even a single cloud.
I'll give you that cloud over there as thanks for when you treated me to a meal.
The plane disappeared behind a cloud and was never seen again.
The kanji and the word are exactly the same. That means they share meanings as well.
This word uses the kun'yomi reading because it's a single kanji on its own. Luckily, that's the reading you learned with the kanji already, so you should be able to read this.