idiotic in WordNet English dictionary

1. incongruous;inviting ridicule
   "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"
   absurd  cockeyed  derisory  idiotic  laughable  ludicrous  nonsensical  preposterous  ridiculous 
   
2. insanely irresponsible
   "an idiotic idea"
   crackbrained  idiotic 
   
3. having a mental age of three to seven years
   imbecile  imbecilic  idiotic