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

detract

to cause (oneself, a person) to become cheap

diminish worth

to speak against (something) especially with sarcasm

criticize, blame

to cause (a person) to be less moral or less deserving of respect

shame, humiliate

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

humble, humiliate

to speak publicly against (a person)

condemn, attack

to take away (from the credit, value etc of something)

take away a part; lessen

to reduce (something) to the smallest amount or degree

make smaller; underrate