Originating from the Eminem song of the same name, "Stan", as a noun, was originally used to describe overly obsessive fans. It has frequently been attributed to K-Pop fans who obsess over boy band members to the point of total infatuation, similar to the "Stan" music video. However, it now seems to be synonymous with "fan" as the word has lost all of its original meaning due to overuse and misuse on social media.
"Omg, I'm such a stan for The Hunchback of Notre Dame!"
By PhattyBolger
A stan is a mix of the words: Stalker and Fan. Stans do too much, like centering emojis around their fandom, accusing others for being stupid for not being apart of the fandom, (etc)
I am a BTS Stan.
By Meanings behind memes
The term “Stan” was derived from the 2000 hit song by the same name created by rapper Eminem. Stan refers to an overly obsessive fan of something, whether is be a YouTuber, musical artist, etc.
“Jane is obsessed with Ed Sheeran.” “Yeah, she’s a stan”
By kaptainquake
Originating from the South Park episode “A Scause for Applause”
I stan for standing
By Doc McG
"Stan" does not mean someone who likes a celebrity. "Stan" is an overly-obsessive fan of a particular celebrity who would go to great lengths for them. "Stan" was a term popularized by Eminem in 2002 when he wrote a song called "Stan," which was about a fan named Stanley Mitchell who was so crazy about Eminem that he put his pregnant girlfriend in the trunk of his car and drove off of a bridge, resulting in their deaths just because Eminem wouldn't respond to his letters.
James: "I love PlayBoi Carti so much... I would die for his music!" Ashley: "Woah, don't be a crazy Stan."
By MayLease