IPA: /ɪmˈpɒv.ər.ɪʃ.ər/
KK: /ɪmˈpɑvərɪʃər/
A person or thing that makes someone or something poor or reduces their wealth.
The impoverisher took away the community's resources, leaving many families in need.
Impoverisher → It is formed from "impoverish" (from Old French *empovrir*, meaning to make poor) and "-er" (meaning a person who). An impoverisher is a person who makes others poor or reduces wealth.
Think of someone who 'makes poor' ('impoverish') — the '-er' indicates that this person is the one doing the action.