What is Mucktard?
1.
When a person acts like somebody with a mental disorder at a certain point in time, but in fact is sane
Devon plays the bass guitar like a mucktard
See 
2.
(n)  What you call someone after they make a stupid remark. A mixture between a 
Person: Do you think Pang Long has groupies?
BBI: WTF!? You mucktard!
See