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
The Chiefs were 0-5 in one-score games and 0-5 when trailing at any point in the second half, an unfathomable reality given the history.
—Sam McDowell 24, Kansas City Star, 24 Nov. 2025
And yet for many years still, some societies fell back on naming deities for the wind, keeping it as an entity under celestial control, or having unfathomable consequences — and not wishing to pry too deeply into what caused it, taking a pre-Enlightenment attitude to it, letting the mystery be.
—Big Think, 18 Nov. 2025
In fact, one scout said the team may end up doing something completely outlandish and unfathomable.
—Robert Marvi, MSNBC Newsweek, 15 Nov. 2025
Ryan and Jason, then respectively 10 and 12, had just watched their little sibling catch on fire, an unfathomable result of the elder two literally playing with fire.
—Zoey Lyttle, PEOPLE, 6 Nov. 2025
See All Example Sentences for unfathomable
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Sam McDowell 24, Kansas City Star, 24 Nov. 2025
And yet for many years still, some societies fell back on naming deities for the wind, keeping it as an entity under celestial control, or having unfathomable consequences — and not wishing to pry too deeply into what caused it, taking a pre-Enlightenment attitude to it, letting the mystery be.
—Big Think, 18 Nov. 2025
In fact, one scout said the team may end up doing something completely outlandish and unfathomable.
—Robert Marvi, MSNBC Newsweek, 15 Nov. 2025
Ryan and Jason, then respectively 10 and 12, had just watched their little sibling catch on fire, an unfathomable result of the elder two literally playing with fire.
—Zoey Lyttle, PEOPLE, 6 Nov. 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 5 Dec. 2025.
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unfathomable
adjective
un·fath·om·able
ˌən-ˈfat͟h-ə-mə-bəl
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