Popular children's game derived from William Shakespear's "Macbeth" - Act 2, Scene 3, line 7, "Knock, knock! Who's there, in th'other devil's name?.."

Epic joke told by character Carl Hanratty (Tom Hanks) in 2002's "Catch Me If You Can".

A fun game in which the participant stands outside a closed door where someone is sleeping. The player pulls out his penis and begins to masturbate. He must stand close enough to the door so his hand knocks on the door as he masturbates. The aim of this fun game is to get off before the sleeping occupants wake up and come to see what all the noise is. While the player technically loses if the occupant comes out of the room too early, the player may be able to get sex out of the occupant should it be an attractive female.

an insult or a threat that one tells to someone else. once the person who replies with "who's there?" the ejoke abruptly ends with the answer "fuck off" many opther endings can be used to make this insult more interesting or more focused on the insultee.

when you just don't care what the hell some one is saying.
Deminstrate this by knocking on an object twice and saying knock knock.

a person who fiend for alcohol alot

To Grab Somebodies attention...slang for pay attention