aka (euphemistically) pain in the butt. A true pain, something damn boring, annoying, offending, labored, troublesome, exhausting or if something just extraordinarily sucks!
Has gotten 'popular' thru J.D. Salinger's catcher in the rye, said various times by the story's main character Holden.
Me: Dude, this math test was a royal pain in the ass!!
Geek: How come I aced it?- $20 from my dad...