Stan
Etymology
From Eminem’s 2000 song "Stan," which portrays a fan whose fixation spirals into tragedy; the name has since been reinforced by echoes of "stalker" and "fan." It shifted from that cautionary character into a general noun and verb for zealous fandom during the 2010s and now appears in mainstream dictionaries. The word carries a faint memory of the obsession that made its origin unsettling.
noun · /stan/
An intensely devoted fan whose enthusiasm shades into obsession, often organized with others into a fiercely protective online fandom.
What it names
It marks the point where admiration becomes identity and defense of the idol becomes a duty, useful for describing fan behavior that outsiders find baffling in its ferocity.
Example
The moment a critic questioned the album, her stans flooded his replies.
Related idea
A parasocial bond is any one-sided attachment to a distant figure; being a stan is that bond amplified into militant, communal devotion.