A person so obsessed with the Xbox or Xbox 360 in such a manner that rational people call them a retard.
Derived from the combination of Xbox(The device which the individual fantasizes over) and retard(used in the slang form to denote lack of intelligence).
At the mention of a superior console, such as the Play Station 3, the xtard became supremely enraged and began shouting about Halo 2 and how great Halo 3 was going to be; all while the rational people backed away slowly so as not to evoke a stupider reaction.
Adj. An extreme and rare act of retardation by a person who is not legally deemed mentally handicaped.
An xtard at a zoo once decided to get a closer picture of a bear by jumping into the exhibit.