IPA: /dɪsˈpærɪdʒər/
KK: /dɪsˈpærɪdʒər/
A person who speaks negatively about someone or something, often to belittle or criticize them.
He was known as a disparager, always finding faults in others' work.
Disparager → It is formed from "dis-" (meaning apart) and "par" (from Latin "parare", meaning to prepare or make equal). The word "disparager" means to speak of someone or something in a way that makes them seem less worthy or equal, effectively putting them apart from others.
Think of someone who makes another feel 'less equal' ('par') by speaking 'apart' ('dis-') from them — that's what disparager means.