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.
And beyond the unfathomable human toll, the costs to consumers and businesses are surging. Scott Cohn, CNBC, 22 July 2025 As the 20th anniversary of Hurricane Katrina approaches in late August, viewers can expect a slew of reflective documentaries confronting that fathomable/unfathomable dichotomy — projects made without expectations of equaling When the Levees Broke, but with a different imperative in mind. Daniel Fienberg, HollywoodReporter, 22 July 2025 Ten years ago, the notion that the U.S. would be financing railway projects in southern Africa would have been considered unfathomable. Jorge Heine, The Conversation, 7 July 2025 Blakely, along with 26 other Camp Mystic girls and counselors, perished in the deluge – forcing her family to endure yet another unfathomable tragedy. Pamela Brown, CNN Money, 18 July 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 8 Aug. 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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