connoisseur

noun
a person with special knowledge or appreciation of a field, esp in the arts
Collins English Dictionary. Copyright © HarperCollins Publishers
Derived forms
connoisseurship (ˌconnoisˈseurship)
noun
Word origin
C18: from French, from Old French conoiseor, from connoistre to know, from Latin cognōscere
https://www.collinsdictionary.com/dictionary/english/connoisseur