A dirty person, that would make a tramp look clean. A doer of un-sanitary things, a complete scruffy scrounging fucker
EXAMPLE 1. Gertrude: hey, I've just farted. In a bag, now I'm going to breathe it in and puke on myself for fun.
Boris: you fuckin "SCRONKER"!
EXAMPLE 2. Mary: I need the toilet
Jim: well go then.
Mary: I can't be bothered.
>1hour later with an oozing stink coming from mary<
Mary: I think I need to go to the toilet I shit myself.
Jim: you fuckin "SCRONKER"!