A person who is so stupid they dont deserve being called a reatard once but twice in the same word. This can also be used when the words fucktard, dumbass, and moron just cant portray and person's lack of simple intellegence.

When you eat dirt for the first time and leave your family to build a shack in the woods

One whose mental deficiency manifests itself as a compulsion to create compound neologisms of the form:

(random derogatory slang term)+("tard.")

In addition to an inability to control this behaviour, the typical tardtard also lives under the delusion that they are being quite witty and/or original.

Unfortunately, the game was won long ago by the brilliant inventor of the original- that venerable old standby; "fucktard."

Nothing since has ever come close, and it is surely not for lack of effort. But every tardtard believes that they will someday coin the next "fucktard," and bask in the immortal glory.

The tardtard is most commonly encountered on Urban Dictionary itself, and is second most common in junior high.

A person who is obsessed with looking up words in the dictionary that are related to the adjective retard.