IPA: /ɪmˈpruːvər/
KK: /ɪmˈpruːvər/
A person or thing that makes something better or enhances its quality.
The new software is a great improver of productivity in the office.
Improver → It is formed from "improve" (from Old French *emprover*, meaning to make better) and "-er" (meaning a person who). An improver is a person who makes something better.
Think of someone who makes things 'better' ('improve') — the '-er' just means a person. An improver is someone who helps improve things.