cretin
     n : a person of subnormal intelligence [syn: {idiot}, {imbecile},
          {moron}, {changeling}, {half-wit}, {retard}]
Source: WordNet® 2.0

cretin /kret'in/ or /kree'tn/ n. Congenital {loser}; an obnoxious
   person; someone who can't do anything right. It has been observed that
   many American hackers tend to favor the British pronunciation /kret'in/
   over standard American /kree'tn/; it is thought this may be due to the
   insidious phonetic influence of Monty Python's Flying Circus.


Source: The Jargon File