to cause (a person, achievement etc) to seem unimportant or of small value

detract

to say or admit (that one has done wrong)

admit, confirm

to make (a person, currency etc) lower in value, poorer in quality etc

degrade, shame

to speak against (something) especially with sarcasm

criticize, blame

to lower (oneself, also a person) in dignity, reputation

humble, humiliate

to laugh at (a person, behaviour etc) and show contempt

make fun of; insult

to behave badly towards (a person); use, handle, (a machine, object) badly

treat badly or wrongly

to say evil things about (a person)

criticize very harshly