Someone who is so amazingly fucking retarded or stupid, it affects your ability to properly speak. Therefore your words run together, making it impossible to say both fucking+retarded, instead pronouncing fuktard. Someone who is at the apex of stupidity, with nothing greater to describe them.
You are a fuktard.
I cant believe this fuktard waited 30 minutes for a parking spot at the store.
Fucking retarded (the past tense)
That was such a fuktarded game
Someone so incredibly stupid that not even they understand themselves.
Fuck an A Samantha, You're a fucktard!
A complete idiot that is so remarkably stupid that they make you extremely angry.
Can also be used as a descriptive term as is "fuktarded" or "fuktardingly"
I can't believe it! Carlos is such a fuktard that he just makes me want to scream!
or
Why would he put a bunny on that car as a hood ornament? That is so fuktarded!