What is another word for connoisseur?

Here are some synonyms for "connoisseur," depending on the specific context:

Formal:

* Expert

* Aficionado

* Specialist

* Authority

* Master

* Virtuoso

* Savant

Informal:

* Fan

* Buff

* Enthusiast

* Addict (for a strong passion)

* Guru (for someone considered a leader in the field)

The best synonym will depend on the specific context of your writing.