arsed
adjective
ˈärst 
British slang, vulgar
: concerned, bothered
The downside is loss of anonymity, but I'm not arsed about that. 
Polly Vernon, Observer (London), 4 Apr. 2010
Polly Vernon, Observer (London), 4 Apr. 2010She'd already written his name and address down for the story and couldn't be arsed [=couldn't be bothered, was too lazy] to try and find another witness. Denise Mina, The Dead Hour, 2006
Denise Mina, The Dead Hour, 2006
Word History
Etymology
arse, verbal derivative of arse ass entry 4 + -ed entry 1
First Known Use
1968, in the meaning defined above