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.

Running for exercise and picking up trash you find along the way. It's good for the body, mind, soul, and environment! Started in Sweden but is making its way to the U. S.