Fan
For the hand tool, please see hand fan.
A fan (derived from fanatic) or buff was a person who had a strong interest in a subject such as an author, sports team, or genre.
Anton Karidian, performer and director of the Karidian Company of Players, had a policy of never meeting with his fans personally. (TOS: "The Conscience of the King")
Vinod described himself as a fan of Golanga, a 24th century soccer player. (DS9: "Paradise")
Elim Garak considered himself a fan of Cardassian literature. (DS9: "Distant Voices")
Julian Bashir was a self-described history buff who found Li Nalas' campaigns against the Cardassians "remarkable". (DS9: "The Homecoming")
Tom Paris, a Mars buff, was surprised at Chakotay's knowledge of the Ares IV mission. (VOY: "One Small Step")