nonsensical

nonsensical
    adj 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" [syn: {absurd}, {cockeyed},
           {derisory}, {idiotic}, {laughable}, {ludicrous},
           {nonsensical}, {preposterous}, {ridiculous}]
    2: having no intelligible meaning; "nonsense syllables"; "a
       nonsensical jumble of words" [syn: {nonsense(a)},
       {nonsensical}]
    

Nonsensical \Non*sen"si*cal\, a.
   Without sense; unmeaning; absurd; foolish; irrational;
   preposterous. -- {Non*sen"si*cal*ly}, adv. --
   {Non*sen"si*cal*ness}, n.
   [1913 Webster]
    

45 Moby Thesaurus words for "nonsensical":
      Pickwickian, absurd, asinine, askew, beyond belief, bizarre,
      cockamamie, crazy, dumb, extravagant, fantastic, fool, foolish,
      grotesque, high-flown, idiotic, imbecilic, incredible, irrational,
      laughable, loony, ludicrous, mad, meaningless, monstrous, moronic,
      nutty, outrageous, outre, poppycockish, preposterous, ridiculous,
      rubbishy, screwball, screwy, senseless, silly, skimble-skamble,
      stupid, trashy, twaddling, twaddly, warped, weird, wild