A verb meaning "to be bothered", and invariably used in the past tense and in conjunction with the words "couldn't be". It originated in the North of England.
"Did you mow the lawn yesterday?
"No - it was too nice a day. I couldn't be arsed."
This usage probably derives from the phrase "to move your arse", meaning to "stir yourself to get something done".
Against the odds, he threw the basket ball from the other end of the court and arsed it in.
He wins a lot of the time, its all arse.
I scored a 1/6 on Worde, obviously it wasn't skill, but all arse.