Undervalue
Part of speech: verb
Definition: to underestimate, or assign too low a value to something to have too little regard for someone
Example sentence: I think the Labour government did good and important things, and it's really important not to undervalue them. I see in my constituency how it helped with education and all those things.
Depreciate
Part of speech: verb
Definition: To reduce in value over time.To belittle
Example sentence: Those who profess to favor freedom, and yet depreciate agitation, are men who want crops without plowing up the ground.