standiversary 

The anniversary of a one night stand that keeps on standing…. Can be weekly, monthly, annually…

The couple celebrated their 2 year standiversary

standiversary by Onmel November 7, 2021

SEAnniversary 

The anniversary of moving to Seattle.

I can’t believe it’s been 7 years since you moved to Seattle. Happy SEAnniversary!

SEAnniversary by kaaali August 1, 2023

saddiversary

An anniversary for a sad, depressing, or generally bad event. Can be used humourously in some cases.

1.
Chuck: "Why so glum, chum?"
Eric: "My dad died a year ago today"
Chuck: "Oh... happy saddiversary dude. I'm sorry"

2.
Larry: "Happy saddiversary Sean!"
Sean: "Huh? What happened today?"
Larry: "Remember last year when you finally dumped that crazy chick you were dating? The one who always bit you while giving head?"
Sean: "Oh yeah... Cheers!"

saddiversary by Misnomer456 October 30, 2010

staniversary 

The yearly anniversary of the date when one started to stan an actor, artist, group, etc.

Tomorrow's my Stray Kids staniversary! I can't believe it's already been a year!

staniversary by stupidbitch15 November 7, 2020