1) Accidentally or even maliciously urinating on a toilet seat (preferably not belonging to the urinator) so as to make the janitor or house owner clean it up
2) A type of bullet cartridge that instead of having the primer cap in the very center of the shell has it along the edge. Most common in .22 practice or hunting ammo.
Tim-Want to go drinking later?
Steve the Busboy-I can't. Someone pulled a rimfire and an upper decker
in the bathroom and I gotta clean it.
Bob-What type of gun you practice with?
Ken-I got a Remington 66 .22 long rimfire
Bob-Pfff that caliber is for pussies
Ken-Don't be a dick