• WordNet 3.6
    • adj thoughtless without care or thought for others; `Let them eat cake'" "the thoughtless saying of a great princess on being informed that the people had no bread"
    • adj thoughtless showing lack of careful thought "the debate turned into thoughtless bickering"
    • ***
Webster's Revised Unabridged Dictionary
    • Thoughtless Deficient in reasoning power; stupid; dull. "Thoughtless as monarch oaks that shade the plain."
    • Thoughtless Giddy; gay; dissipated.
    • Thoughtless Lacking thought; careless; inconsiderate; rash; as, a thoughtless person, or act.
    • ***
Century Dictionary and Cyclopedia
    • thoughtless Devoid of or lacking capacity for thought.
    • thoughtless Unthinking; heedless; careless; giddy.
    • thoughtless Synonyms Heedless, Remiss, etc. (see negligent), regardless, inattentive, inconsiderate, unmindful, flighty, harebrained.
    • ***
Chambers's Twentieth Century Dictionary
    • adj Thoughtless without thought or care: careless: inattentive: stupid: dull
    • ***


  • James Baldwin
    “Rage cannot be hidden, it can only be dissembled. This dissembling deludes the thoughtless, and strengthens rage and adds, to rage, contempt.”
  • Marquis De Vauvenargues
    “Most people grow old within a small circle of ideas, which they have not discovered for themselves. There are perhaps less wrong-minded people than thoughtless.”
  • Desiderius Erasmus
    “The more ignorant, reckless and thoughtless a doctor is, the higher his reputation soars even amongst powerful princes.”
  • Percy Bysshe Shelley
    “Government is an evil; it is only the thoughtlessness and vices of men that make it a necessary evil. When all men are good and wise, government will of itself decay.”
  • Hannah More
    “Love never reasons, but profusely gives; it gives like a thoughtless prodigal its all, and then trembles least it has done to little.”
  • Cyril Connolly
    “In the sex war, thoughtlessness is the weapon of the male, vindictiveness of the female.”


Chambers's Twentieth Century Dictionary
A.S. ge-thóht; Ice. thóttr, Ger. bedacht. Cf. Think.


In literature:

How I regretted my thoughtlessness in not having forestalled myself in the Sutherlands' barge.
"Lords of the North" by A. C. Laut
Forgive me, Edith, for being so thoughtless and impulsive; for being so selfish myself.
"Ernest Linwood" by Caroline Lee Hentz
Let her have two or three years, even if it was blissful thoughtlessness.
"A Little Girl in Old Salem" by Amanda Minnie Douglas
She was beautiful and thoughtless; she appreciated her position as the daughter of a king.
"Lucretia Borgia" by Ferdinand Gregorovius
Throughout the whole history of the race they have been kindly, thoughtless children.
"The Girl in the Golden Atom" by Raymond King Cummings
You can be happy without being thoughtless.
"The Fortunes of the Farrells" by Mrs. George de Horne Vaizey
It was only thoughtlessness.
"The Heart of Una Sackville" by Mrs. George de Horne Vaizey
It's right unthankful of her not to mend; but childre is that thoughtless!
"All's Well" by Emily Sarah Holt
Many ignorant or thoughtless parents and nurses constantly use fear as a means of governing children.
"Pushing to the Front" by Orison Swett Marden
Oh, you thoughtless men!
"In the Eastern Seas" by W.H.G. Kingston

In poetry:

Thou thinkest I who follow thee
Am but a thoughtless boy,
That warbles, like the forest birds,
From fullness of my joy.
"The Little Serving-Boy" by Cicely Fox Smith
Men void of wisdom and of grace,
If honor raise them high,
Live like the beast, a thoughtless race,
And like the beast they die.
"Psalm 49 part 1" by Isaac Watts
The sire himself, with gesture wild,
His thoughtless offspring takes;
And seats his unoffending child
Amidst these angry Snakes!
"The Serpents" by William Hayley
"RETURN, return, my hapless spouse,
Nor seek the fatal place,
Where thoughtless crowds expecting stand
To see thy child's disgrace.
"A Ballad" by Jane Bowdler
Not for the thoughtless:,they will brush
Thy leaf without a care,
Perhaps will tread thee to the earth,
Nor heed that thou art there.
"Sent To A Friend With A Wild Flower, Called "The Simpler's Joy"" by Caroline Fry
Time has been when, like thee thoughtless,
How unlike in all beside!
Lightly sped, and all uncounted,
Blithe I saw the moments glide.
"On Seeing Some Butterflies In A Clover Field On The Sabbath" by Caroline Fry

In news:

One who thoughtlessly serves the people, with little thought for their self.
Done thoughtlessly and in poor taste, it certainly can be.
Our friends and family members are seldom so thoughtless as to call at that particular time.
Once the fighting stopped, the major powers were content to pursue a thoughtless, hollow democratization.
A foolish or thoughtless young person.
Thoughtless retaining of judges can't be considered a success.
No scale exists for thoughtless cash gifts.
Reaction on Twitter at times emotional, thoughtless .
Thoughtless actions threaten peace of mind.
Two months ago, a lady thought­lessly crashed into my car and cre­ated exten­sive dam­age to the left front fender and my body.
With bottles retailing in the $32,000 range, this was not a shot to be downed thoughtlessly.
With politicians saying really thoughtless and stupid things that spur outrage, not one has stepped down from office.
Gerould Kern didn't say anything thoughtless or unreasonable at Thursday's media forum at the Newberry Library, so why pick at nits.
Court Closure Called 'Thoughtless And Insensitive '.
Obama's Mideast strategy muddled , thoughtless.

In science:

Thus, should be taken only as a warning against thoughtless application of formal conclusions of the Davies theory to, e.g., diffusion flows where no such flows exist.
Stationary flows in quantum dissipative closed circuits as a challenge to thermodynamics
Epstein J M (2001) Learning to be thoughtless: Social norms and individual computation.
Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach
Ferrero and Santos refer to Einstein’s words , according to whom physical ob jects are “thoughtless arranged in a space-time continuum.
A realistic interpretation for quantum mechanics