I'll freeze any food that's left over

I found the example sentence in a dictionary as below:
I’ll freeze any food that’s left over.

Question: The words “left over” here is used as a verb or as a noun?

Thank you!!!

“left over” here is an adjective describing the food. “is” is the verb…it’s in the contraction that’s. that’s = that is.

left over - Wiktionary

Also, “Left Over or Leftover – What’s the Difference?”
Left Over or Leftover – What’s the Difference? - Writing Explained