IPA: /əˈpriːʃieɪtə/
KK: /əˈpriːʃieɪtər/
A person who recognizes the value or quality of something and enjoys it.
As an art appreciator, she spends her weekends visiting galleries and exhibitions.
Appreciator is formed from "appreciate" (from Latin "appretiare", meaning to value or estimate) and "-or" (meaning one who). The word "appreciator" refers to one who values or recognizes the worth of something.
Think of someone who 'values' ('appretiare') something — that's why an 'appreciator' is someone who recognizes its worth.