A Jack Tard idiot is a cross between a Jack Ass and Tard. Jack tards are not responsible for their actions, although they should be. Usually mucking up things for the rest of society.
That Jack Tard took up two spaces in a car lot. Jack tards write checks in an express lane. Also, Jack tards don't know the difference between merging and yielding on a highway.
person who is being stupid or just fuckin retarded
"Dude, Stop being such a fucking Jack tard!"