deprecate
Meaning: to belittle, depreciate
Usage: Always over-modest, he deprecated his contribution to the local charity.
denigrate
Meaning: to belittle, diminish the opinion of
Usage: The company decided that its advertisements would no longer denigrate the company’s competitors.
debase
Meaning: to lower the quality or esteem of something
Usage: The large raise that he gave himself debased his motives for running the charity.
demean
Meaning: to lower the status or stature of something
Usage: She refused to demean her secretary by making him order her lunch.
vilify
Meaning: to lower in importance, defame
Usage: After the Watergate scandal, almost any story written about President Nixon sought to vilify him and criticize his behavior.
abase
Meaning: to humiliate, degrade
Usage: After being overthrown and abased, the deposed leader offered to bow down to his conqueror.