Arse, backside, ass, batty, back crack
Whilst holding a stick, ''You wouldn't want that up your jacksie!!!''
Jacksie is Cockney Rhyming Slang.
It means backside, bottom, arse...
The word comes from : Jacksie = Jack and Danny = Fanny.
It's not a synonym for fanny though.
You can shove your Sony PSP right up your jacksie