One step up from a nightmare, bad news, or an annoying person!
"Dude, that girl is an absolute shitemare!"
"The party was a complete shitemare!"
1) To find oneself in a public toilet that is lacking a door lock, a toilet seat or a loo roll
2) Any situation in which poo becomes a visible nuisance
1) "Aww man. there's no toilet paper up in this smelly joint. What a shitemare."
"I've got paper for you buddy, in return for a little something something that is."
"Ted? Is that you?"
"It was always me Bill, it was always me."
2) The Indian Commonwealth Games