Reduce in importance or value (9)

I believe the answer is:

downgrade

(Other definitions for downgrade that I've seen before include "Relegate" , "Reduce in rank or value" , "Reduce to lower level" , "Depressed" , "Sell short" .)

I've seen this clue in The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.