[1] : The Collaborative International Dictionary of English v.0.48

idiotic \id`iot"ic\, idiotical \id`iot"ical\, a. l.
   idioticus ignorant, gr. ?: cf. f. idiotique. see idiot.
   1. common; simple. obs. --blackwall.
      1913 webster

   2. pertaining to, or like, an idiot; characterized by idiocy;
      foolish; fatuous; as, an idiotic person, speech, laugh, or
      action.
      1913 webster
see also:
idiot 

[2] : WordNet (r) 2.0

idiotic
     adj 1: insanely irresponsible; "an idiotic idea" syn: crackbrained
     2: completely devoid of wisdom or good sense; "the absurd
        excuse that the dog ate his homework"; "that's a cockeyed
        idea"; "ask a nonsensical question and get a nonsensical
        answer"; "a contribution so small as to be laughable"; "it
        is ludicrous to call a cottage a mansion"; "a preposterous
        attempt to turn back the pages of history"; "her conceited
        assumption of universal interest in her rather dull
        children was ridiculous" syn: absurd, cockeyed, derisory,
         laughable, ludicrous, nonsensical, preposterous,
        ridiculous
     3: having a mental age of three to seven years syn: imbecile,
         imbecilic
see also:
crackbrained absurd cockeyed derisory laughable ludicrous 
nonsensical preposterous ridiculous imbecile imbecilic 

[3] : Moby Thesaurus II by Grady Ward, 1.0

78 moby thesaurus words for "idiotic":
   apish, arrested, asinine, babbling, backward, batty, befooled,
   beguiled, besotted, blithering, brainless, buffoonish, burbling,
   cockeyed, crackbrained, cracked, crazy, credulous, cretinistic,
   cretinous, daffy, daft, dazed, dithering, dizzy, doting, driveling,
   drooling, dumb, fatuitous, fatuous, flaky, fond, fool, foolheaded,
   foolish, fuddled, futile, gaga, goofy, gulled, half-baked,
   half-witted, imbecile, imbecilic, inane, inept, infatuated, insane,
   kooky, loony, mad, maudlin, maundering, mentally defective,
   mentally deficient, mentally handicapped, mentally retarded,
   mongoloid, moronic, not all there, nutty, retarded, sappy, screwy,
   senseless, sentimental, silly, simple, simpleminded, simpletonian,
   slobbering, stupid, subnormal, thoughtless, wacky, wet, witless

Idiotic >> I Words
Idiotic, definition of term: Idiotic
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