Most famously featured on the show, iCarly, a hob knocker is a word mainly used by English people. In real definition, a hob knocker is a man, during oral sex, hitting a woman in the face with his dick
On iCarly, it is described as illegal. In actuality, it isn't. It's just really fun
Filmer: Hey, Joe! Be a hob knocker and whack the slut with your dick!
An allegedly defamatory aspersion of ostensible British origon used chiefly to assert the recipient's overt practice of something decidedly "gross" and "illegal"; as spoken in the American sitcom television series "iCarly".