Synonyms of 'fancier'
If someone is an aficionado of something, they like it and know a lot about it.
You are obviously a jazz aficionado.
A connoisseur is someone who knows a lot about the arts, food, drink, or some other subject.
I hear you're something of an art connoisseur.
An expert is a person who is very skilled at doing something or who knows a lot about a particular subject.
an expert in computer graphics
boffin (British , informal)
rocket scientist (informal , US)
dab hand (British , informal)
fundi (South Africa)
Thesaurus for fancier from the Collins English Thesaurus
An animal or plant fancier is a person who breeds animals or plants of a particular type or who is very interested in them.