The air conditioning was working well in the house.
Thank you for giving me a response while you were busy.
The parents were sitting with their child between them.
The kanji and the word are exactly the same. That means they share meanings as well.
Since this word is made up of a single kanji, it uses the kun'yomi reading. When learning the kanji, you didn't learn that reading, so here's a mnemonic to help you with this word:
Something is coming from the middle of the wall. It sounds like a knock (なか), knock, knock noise. You break down the wall, and sure enough there's some creepy dude standing inside. He is the knocker.