Gong Bag

Noun

A person of limited intelligence, with poor judgment, and who is oblivious to their surroundings and inconsiderate.

Synonyms: Dummy, Numpty, Wanker, Imbecile.

“Did you hear that guy talking shit at lunch? What a Gong Bag!” or “Hey, taste the biscuit, Gong Bag! (I.E. Get Fucked, Asshole)”