That thing with the thing that does that thing....you know what I'm talking about. Accually when you don't know what something is and you pretend you "forgot it." There for you call it this.
Person 1-Good golly I saw that thing today.
Person 2-What thing are you refering to?
Person 1-Oh you know the thing-a-ma-bob.
Person 2- Oh ya that thing.
Person 1-Indeed Person 2- (thinking "Damn what a douche bag!)