IPA: //ˈdɛnɪɡreɪtər//
KK: /dɛnɪˌɡreɪtər/
A person who speaks negatively about someone or something, often to belittle or criticize them unfairly.
He was known as a denigrator, always putting others down to make himself feel better.
Denigrator → It is formed from "de-" (meaning down or away) and "niger" (meaning black). The suffix "-ator" indicates a person who performs an action. Thus, a denigrator is someone who brings down or blackens the reputation of another.
Think of someone who 'brings down' ('de-') the 'blackness' ('niger') of another's reputation — that's why a denigrator is someone who disparages or belittles.