http://www.dictionary.com also lists this definition of cretin, apparently from computer jargon:

cretin 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.