Dirty, unpleasant, or in bad condition.
Scungy things are not nice and can make people feel yucky or uncomfortable.
Examples:
The scungy old couch was thrown out.
She wore a scungy old hat.
The scungy cat looked sad.
I don't want to touch that scungy thing!
The scungy pond was full of gross stuff.
He lived in a scungy old house with a leaky roof.