fan•girl /'fangerl/ noun Plural noun: Fangirls Informal derogatory an obsessive female fan (usually of movies, comic books, or science fiction) now that's Google's definition of a fangirl, but what really is a fangirl? And how does one even become a fangirl? Well my friends, you've come to the right place. This is the amazing guide in which one normal teen becomes an obsessive fangirl. Disclaimer// this story is meant for amusement purposes, if you become antisocial af and crazy it's not our fault. but it's okay if you do because now you're a fangirl, welcome to the club.