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.
The scale of the devastation is unfathomable. R. Daniel Foster, Forbes.com, 27 Aug. 2025 This conflict has a way of sanitizing what at one time was unfathomable, converting obnoxious practices into acceptable behavior. Hussein Agha, New Yorker, 22 Aug. 2025 Turner slugged his first home run at home all season, an unfathomable streak broken. Matt Gelb, New York Times, 19 Aug. 2025 But carrying around a little mini garbage can for our butts is unfathomable. Jeremy D. Larson, Pitchfork, 14 Aug. 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 9 Sep. 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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