unfathomable
adjective
un·fath·om·able
ˌən-ˈfa-t͟hə-mə-bəl 
: not capable of being fathomed:
a
: immeasurable
… the unfathomable darkness of empty space.—
H. G. Wells
H. G. Wells
b
: impossible to comprehend
unfathomable motives/reasons
Examples of unfathomable in a Sentence
His behavior is completely unfathomable.
the unfathomable reaches of space
Recent Examples on the Web
Advisers were on hand to teach them the nuances of the Situation Room and the importance of maintaining calm under unfathomable stress.
—Patrick Ryan, USA Today, 21 Oct. 2025
That may sound unfathomable to any non-comic reader who watched Steven Yeun's Mark Grayson get bludgeoned, maimed, and nearly disemboweled (sorry, Atom Eve) in an episode-long, cities-spanning fight with Thragg's berzerker warrior, Conquest (Jeffrey Dean Morgan).
—Nick Romano, Entertainment Weekly, 10 Oct. 2025
Not after another season of beautiful dreams ended in the most painful, most unfathomable way possible, even by Phillies standards.
—Jayson Stark, New York Times, 10 Oct. 2025
That's unfathomable, that's unacceptable, that's unconscionable, and that's un-American.
—John Parkinson, ABC News, 30 Sep. 2025
See All Example Sentences for unfathomable
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Patrick Ryan, USA Today, 21 Oct. 2025
That may sound unfathomable to any non-comic reader who watched Steven Yeun's Mark Grayson get bludgeoned, maimed, and nearly disemboweled (sorry, Atom Eve) in an episode-long, cities-spanning fight with Thragg's berzerker warrior, Conquest (Jeffrey Dean Morgan).
—Nick Romano, Entertainment Weekly, 10 Oct. 2025
Not after another season of beautiful dreams ended in the most painful, most unfathomable way possible, even by Phillies standards.
—Jayson Stark, New York Times, 10 Oct. 2025
That's unfathomable, that's unacceptable, that's unconscionable, and that's un-American.
—John Parkinson, ABC News, 30 Sep. 2025
See All Example Sentences for unfathomable
Cite this Entry
“Unfathomable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unfathomable. Accessed 11 Nov. 2025.
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unfathomable
adjective
un·fath·om·able
ˌən-ˈfat͟h-ə-mə-bəl
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