While I listened to my mother talk, I nodded, "Uh huh."
If you want to show your agreement with someone you need to nod at them so they know.
The reading for this word is an exception. Here's a mnemonic to help you remember it:
You seem to nod your head a lot when you're at the unagi zoo (うなず). Unagi zoos are really rare and hard to get into. So while you're there to keep nodding to everyone because you're so honored to be there!