A word that is almost exclusively used in
Northern Ireland.
It is a rather simple insult/comeback, it means 'suck the back of them' with 'them' being testicles.
For non-Northern
Irish people it is
pronounced 'sucka-backy-im'. That's IM as in TIM.
John: Here mate that's my
football, giz it back ya wank
James: Na mate my ma got me this one
John: Mate, its
the same ball, just giz it back!
James, Na suckabackyem ye ain't
gettin it.