thoughtless

from WordNet (r) 3.0 (2006)
thoughtless
    adj 1: showing lack of careful thought; "the debate turned into
           thoughtless bickering" [ant: {thoughtful}]
    2: without care or thought for others; "the thoughtless saying
       of a great princess on being informed that the people had no
       bread; `Let them eat cake'" [syn: {thoughtless}, {uncaring},
       {unthinking}]
    
from The Collaborative International Dictionary of English v.0.48
Thoughtless \Thought"less\, adv.
   1. Lacking thought; careless; inconsiderate; rash; as, a
      thoughtless person, or act.
      [1913 Webster]

   2. Giddy; gay; dissipated. [R.] --Johnson.
      [1913 Webster]

   3. Deficient in reasoning power; stupid; dull.
      [1913 Webster]

            Thoughtless as monarch oaks that shade the plain.
                                                  --Dryden.
      [1913 Webster] -- {Thought"less*ly}, adv. --
      {Thought"less*ness}, n.
      [1913 Webster]
    
from Moby Thesaurus II by Grady Ward, 1.0
217 Moby Thesaurus words for "thoughtless":
      absent-minded, airy, apish, arbitrary, artless, asinine, batty,
      befooled, beguiled, besotted, blank, blankminded, brainless, brash,
      buffoonish, calm, capricious, careless, casual, cockeyed, crazy,
      credulous, cursory, daffy, daft, dazed, degage, discourteous,
      disregardant, disregardful, distracted, distrait, dizzy, doting,
      dumb, easygoing, empty, empty-headed, fatuitous, fatuous,
      featherbrained, featherheaded, feckless, flaky, flippant, fluttery,
      fond, fool, foolheaded, foolish, forgetful, free and easy,
      frivolous, fuddled, futile, gaga, giddy, giddy-brained,
      giddy-headed, giddy-pated, giddy-witted, goofy, grasshopper,
      gulled, half-assed, happy-go-lucky, harebrain, harebrained, hasty,
      heedless, hotheaded, idiotic, ill-advised, ill-considered,
      ill-contrived, ill-devised, ill-gauged, ill-judged, imbecile,
      impolite, impolitic, improvident, imprudent, inadept, inadvertent,
      inadvisable, inane, inapt, inattentive, incautious, incogitant,
      inconsiderate, incurious, indifferent, indiscreet, inefficient,
      inept, inexpedient, inexpert, infatuated, injudicious, inobservant,
      insane, insensate, insensitive, insouciant, irrational, kooky,
      lazy, loony, mad, madcap, maudlin, mediocre, mindless, misadvised,
      misguided, moronic, myopic, neglectful, negligent, nirvanic, nutty,
      oblivious, offhand, passive, pedestrian, perfunctory, poor,
      quietistic, rash, rattlebrained, rattleheaded, rattlepated,
      reasonless, reckless, regardless, relaxed, remiss, respectless,
      rude, sappy, scatterbrained, scramblebrained, screwy, selfish,
      senseless, sentimental, sharp, shatterbrained, shiftless,
      shortsighted, silly, skill-less, stupid, tactless, thoughtfree,
      thriftless, tranquil, unaccommodating, unadvised, unapt,
      uncalculating, uncaring, unceremonious, uncomplaisant,
      unconsidered, uncooperative, undeft, undexterous, undextrous,
      undiplomatic, undiscerning, uneconomical, unfacile, unforeseeing,
      ungracious, unguarded, unheedful, unheeding, unhelpful, unideaed,
      unintellectual, unintelligent, unmarking, unmindful, unnoticing,
      unnoting, unobliging, unobservant, unobserving, unoccupied,
      unprepared, unproficient, unproviding, unready, unreasonable,
      unreasoning, unreflecting, unreflective, unremarking, unseeing,
      unsensible, unskillful, unsolicitous, unsound, untactful,
      unthinking, unthoughtful, unthrifty, unwise, vacant, vacuous,
      wacky, wet, witless, wrecking

    

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