Definitions by ringbark

YDKJ 

You don't know Jack...

Abbreviation for a popular computer game available in the 1990s and 2000s both online and as a boxed game. It contains pop culture questions, often phrased in a manner laden with innuendo.

Derives from the slang phrase "you don't know jack shit".

A bunch of friends are coming round for a couple of beers and a pizza and we're gonna play YDKJ. You up for it?

YDKJ by ringbark November 18, 2007