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.
This was the president of the United States’s defense of his national security adviser who’s embroiled in a humiliating, alarming, and downright unfathomable breach of security — and confidence. S.e. Cupp, New York Daily News, 27 Mar. 2025 That ability to maintain realistic championship expectations would’ve been unfathomable to think of nine years ago, before Muzerall arrived from Minnesota. Cameron Teague Robinson, New York Times, 27 Mar. 2025 All of this raises a question that was unfathomable until recently: Is the nation’s capital, so long blessed by being the government’s company town, at risk of a fate resembling that of so many other company towns through the years? Alec MacGillis, ProPublica, 13 Mar. 2025 By 2025, we’re predicted to reach an almost unfathomable 181 zettabytes. Ann Kowal Smith, Forbes, 25 Feb. 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 11 Apr. 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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