unfathomable

unfathomable
adjective
un·;fath·;om·;able ;;n-;fa-t;h;-m;-b;l
Synonyms of unfathomable
: not capable of being fathomed:
a
: immeasurable
b
: impossible to comprehend
unfathomably
;;n-;fa-t;h;-m;-bl;
 adverb

Synonyms
bottomless
boundless
endless
fathomless
horizonless
illimitable
immeasurable
immensurable
indefinite
infinite
limitless
measureless
unbounded
unlimited
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. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
For the past 30 years, the most trivial motions in his day required unfathomable patience.
—Stephanie Stremplewski, The Courier-Journal, 28 Nov. 2024
Meanwhile, upsets over visiting Ole Miss and LSU the past two weeks will send the Gators to a bowl, something that seemed unfathomable a few weeks ago.
—Tom Layberger, Forbes, 27 Nov. 2024
The news that Alex had fired a gun — taking her own life — was unfathomable to Alex's parents Mary Jo and Jim Pennig.
—Natalie Morales, CBS News, 26 Oct. 2024
That seemed unfathomable to players and coaches in both dugouts, to Padres pitcher Dylan Cease and to just about everyone in a sellout crowd of 53,028.
—Mike Digiovanna, Los Angeles Times, 6 Oct. 2024

Word History
First Known Use
1640, in the meaning defined above

Time Traveler
The first known use of unfathomable was in 1640
See more words from the same year
Dictionary Entries Near unfathomable
unfatherly

unfathomable

unfathomed