groupie

noun4

1. •
   A fan, especially a young female fan of a male singer or rock group, who seeks intimacy (most often physical, sometimes emotional) with a celebrity; usually with a rock 'n' roll artist or band member.
2. •
   (informal) Any dedicated fan of something.

   • A bit of an eclipse groupie, he had paid the thirty guineas fee to join the BAA's first expedition, to Norway, in 1896. — 2019
3. •
   A group photo including the photographer; a group self-portrait.
4. •
   (slang) A group captain.

   • In traditional military fashion our "Groupie" (group captain) called us to attention, exchanged salutes with his German opposite number, then handed the parade over to him. — 1995