Noun: A name reserved for someone who is so annoying and stupid that no word can accurately describe them, and all that comes to mind is a "fucking retard." Hence, you have the fucktard.
Adjective: A word to describe a person who is just a fucking retard. Not to be confused with people who are actually mentally retarded; Fucktards are merely socially retarded.
1. "So Jillian just told me that she has a huge crush on Nate, and that she plans on stealing him from his ugly-ass girlfriend. Everyone at school knows that Nate and I are dating...Jillian is such a fucktard!"