Also found in: Thesaurus.


1. Impossible to imagine; inconceivable: "The inert gases have been coaxed into combination, and I have seen a fluoride of xenon, unthinkable in the 1940s" (Oliver Sacks).
2. Not worth considering because of being socially unacceptable, too difficult, or too risky: Raising taxes was politically unthinkable.
3. Abhorrent; monstrous: unthinkable brutality.

un·think′a·bil′i·ty, un·think′a·ble·ness n.
un·think′a·bly adv.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adv.1.unthinkably - to an unimaginable extentunthinkably - to an unimaginable extent    
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
Mentioned in ?
References in classic literature ?
"Now that you are about to die the most unthinkably horrid death that it is given a white man to die--let this word of the plight of your wife add to the torments that you must suffer before the last savage spear-thrust releases you from your torture."
Above him, falling upon him like a bolt from the blue, was a winged hawk unthinkably vaster than the one he had encountered.
And yet, in the good time coming when alcohol is eliminated from the needs and the institutions of men, it will be the Y.M.C.A., and similar unthinkably better and wiser and more virile congregating-places, that will receive the men who now go to saloons to find themselves and one another.
Ten thousand unthinkably atrocious deaths could not atone for the affront that you have put upon me.
You know the wonder of a woman's arm--the fore arm, I mean; the sweet fading away from rounded biceps and hint of muscle, down through small elbow and firm soft swell to the wrist, small, unthinkably small and round and strong.
One--twice--thrice that terrifying cry rang out across the teeming solitude of that unspeakably quick, yet unthinkably dead, world.
Yet now, resolutely, as only a man can do who is capable of martyring himself for the cause of science, he proceeded to violate all the fineness and delicacy of his nature by making love to the unthinkably disgusting bushwoman.
Her home was unthinkably filthy; you could not enter by the front door at all, owing to the mattresses, and when you tried to go up the backstairs you found that she had walled up most of the porch with old boards to make a place to keep her chickens.
Such a forest, such a jungle might have stood there in the beginning of that unthinkably far-gone age before God peopled the world with life, when there were no sounds because there were no ears to hear.
"St Richard's Hospice provides a muchneeded support and care system for those going through unthinkably hard times, therefore sponsoring this event was a no brainer."
And, in the absence of religious beliefs and traditions, in the unthinkably far mental distance from biblical or Talmudic narratives, it was the family lore of war stories that constituted the sacred text of the Russian Jewish experience.
Unthinkably, sexual tension simmers between Rachael and Stefan, and when Lewis is called away to deal with a crisis, passions boil over.