unfathomable

adjective

un·​fath·​om·​able ˌən-ˈfa-t͟hə-mə-bəl How to pronounce unfathomable (audio)
: not capable of being fathomed:
b
: impossible to comprehend
unfathomably adverb

Examples of unfathomable in a Sentence

His behavior is completely unfathomable. the unfathomable reaches of space
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
That's unfathomable, that's unacceptable, that's unconscionable, and that's un-American. John Parkinson, ABC News, 30 Sep. 2025 The idea of the Tigers making a deep October run would be unprecedented but not unfathomable. Cody Stavenhagen, New York Times, 29 Sep. 2025 Since June 12, the Mets went 38-55 – an unfathomable skid considering their early dominance. Scott Thompson, FOXNews.com, 29 Sep. 2025 The concept has never been tested in the real world, and the unfathomable risks include the danger that cables could snap, causing entire rigs to capsize in storms, creating debris fields along the Pacific Coast. Craig Rucker, Boston Herald, 26 Sep. 2025 See All Example Sentences for unfathomable

Word History

First Known Use

1640, in the meaning defined above

Time Traveler
The first known use of unfathomable was in 1640

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Cite this Entry

“Unfathomable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unfathomable. Accessed 4 Oct. 2025.

Kids Definition

unfathomable

adjective
un·​fath·​om·​able ˌən-ˈfat͟h-ə-mə-bəl How to pronounce unfathomable (audio)
: not capable of being fathomed:
b
: impossible to understand

More from Merriam-Webster on unfathomable

Last Updated: - Updated example sentences
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