A fork of Rural Dictionary
The anniversary of the date you entered a fandom, based on whatever you consider the genesis of becoming a fan.
"You know, one year ago today I drew my first "Harry Potter" fanart." "Oh my God, like, happy one year fanniversary!"
The yearly Celebration of a Transgender woman successfully completing Gender Reassignment/Confirmation Surgery
Today is my Fanniversary, it's 20 years since I became a complete Woman...