fath·​om | \ ˈfa-t͟həm How to pronounce fathom (audio) \

Definition of fathom

 (Entry 1 of 2)

1 : a unit of length equal to six feet (1.83 meters) used especially for measuring the depth of water sometimes used in the singular when qualified by a number five fathom deep
2 : comprehension the themes display a newer fathom than the technical modernism of the composer's earlier worksNewsweek


fathomed; fathoming; fathoms

Definition of fathom (Entry 2 of 2)

intransitive verb

1 : probe
2 : to take soundings

transitive verb

1 : to measure by a sounding line
2 : to penetrate and come to understand couldn't fathom the problem

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Other Words from fathom


fathomable \ ˈfa-​t͟hə-​mə-​bəl How to pronounce fathom (audio) \ adjective

Synonyms for fathom

Synonyms: Verb

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Did fathom Always Refer to a Measurement?


Fathom comes to us from Old English fæthm, meaning "outstretched arms." The noun fathom, which now commonly refers to a measure (especially of depth) of six feet, was originally used for the distance, fingertip to fingertip, created by stretching one's arms straight out from the sides of the body. In one of its earliest uses, the verb fathom meant to encircle something with the arms as if for measuring and was also a synonym for "embrace." In the 1600s, however, fathom took on the meaning of using a sounding line to measure depth. At the same time, the verb also developed senses synonymous with "probe" or "investigate," and is now frequently used to refer to the act of getting to the bottom of something (figuratively speaking).

Examples of fathom in a Sentence

Noun The water here is five fathoms deep. Verb the pilot had to continually fathom the river, which drought conditions had lowered to unprecedented levels
Recent Examples on the Web: Noun But in today’s world of restrictions on size, quantity and season, releasing reef fish has become part of our new reality—as are the challenges of ensuring postrelease survival for an animal pulled up from 20 fathoms. Popular Science, "Releasing a caught fish isn’t as simple as tossing it overboard," 11 Feb. 2020 That impulse, growing out of one pivotal song, eventually pointed the way to the fathoms of Ocean, the group’s new album, their seventh, which debuts Friday. Nancy Kruh, PEOPLE.com, "After Overcoming a 'Band Mid-Life Crisis,' Lady Antebellum Plumbs the Depths in Ocean," 15 Nov. 2019 The lines were marked at two, three, five, seven, 10, 13, 15, 17 and 20 fathoms. Richard Lederer, San Diego Union-Tribune, "The English language always has your number," 19 Oct. 2019 The submarine is recorded in 1,805 fathoms of water, or 8,310 feet, and makes a test dive. Kyle Mizokami, Popular Mechanics, "Come Take a Tour of America's Newest Nuclear Submarine," 7 Jan. 2019 Leadbetter Point to Cape Falcon - Nearshore (inside 40 fathoms) opens May 7; Mondays to Wednesdays until 500 pounds are caught or Sept. 30. Bill Monroe, OregonLive.com, "Summer ocean fishing, fall hunting seasons set for Oregon," 20 Apr. 2018 Get ready to be terrified by the mysterious fathoms below! Laura Beck, Cosmopolitan, "The Trailer for 'Siren,' a Terrifying (and Kinda Sexy?!) New Show About Mermaids Is Freaky-as-Hell," 27 Jan. 2018 More than 200 years later, our low tide was at the same time Cook's high had been, and 4 fathoms — 24 feet — was an understatement. Erin Mckittrick, Alaska Dispatch News, "Meandering the mudflats: 800 miles around Cook Inlet," 15 Sep. 2017 Captain Cook filled his logs with notes on the tide, on the time the ebb began each day, the force of the current, the fathoms of water, or lack of water, beneath his ship. Erin Mckittrick, Alaska Dispatch News, "Meandering the mudflats: 800 miles around Cook Inlet," 15 Sep. 2017 Recent Examples on the Web: Verb Abdulaziz Mohamed can hardly fathom the idea of having his student loan debt wiped away. Ryan Faircloth, Star Tribune, "Young Minnesotans excited about Biden's pitch to cancel $10,000 in student loan debt," 27 Jan. 2021 The reason the book connected this year is not hard to fathom, given what has happened in our nation and world. Globe Staff, BostonGlobe.com, "The Fast Forward 2020 Winter Bookies reading list," 4 Jan. 2021 Still, said some gun sellers, the jump from 2019 to last year’s record NICS checks and gun sales was hard to fathom. Paul Bedard, Washington Examiner, "Historic: FBI logs 40% jump in gun checks in 2020, a record 39M," 4 Jan. 2021 Which is why Herbstreit — and so many others — couldn't fathom Saturday night’s performance. Shawn Windsor, Detroit Free Press, "Michigan football needs the old Jim Harbaugh to rescue them. He showed up Monday," 16 Nov. 2020 That’s almost impossible to fathom in modern college football. Dan Wolken, USA TODAY, "Opinion: Michigan loss to Michigan State is worst and most surprising of Jim Harbaugh era," 1 Nov. 2020 For diners, the loss of these beloved community spaces is hard to fathom. Tara Duggan, SFChronicle.com, "The most significant San Francisco Bay Area restaurant closures of 2020," 16 Dec. 2020 Now in their 46th year of decorating, the Banases couldn’t fathom not putting up their ever-changing display of winter goodies, even if the pandemic makes things less fun. Michelle L. Quinn, chicagotribune.com, "For the 46th year, house in Highland continues to spread joy amid the COVID-19 pandemic," 9 Dec. 2020 Most simply cannot fathom why anyone would ever like Biden more than Trump. Washington Post, "What it’s like to teach children about the election, and its results, in deep-red Trump country," 29 Nov. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fathom.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of fathom


before the 12th century, in the meaning defined at sense 1


1607, in the meaning defined at intransitive sense 1

History and Etymology for fathom

Noun and Verb

Middle English fadme, from Old English fæthm outstretched arms, length of the outstretched arms; akin to Old Norse fathmr fathom, Latin patēre to be open, pandere to spread out, Greek petannynai

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Time Traveler for fathom

Time Traveler

The first known use of fathom was before the 12th century

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Cite this Entry

“Fathom.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fathom. Accessed 5 Mar. 2021.

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More Definitions for fathom



English Language Learners Definition of fathom

 (Entry 1 of 2)

: a unit of length equal to six feet (about 1.8 meters) used especially for measuring the depth of water



English Language Learners Definition of fathom (Entry 2 of 2)

: to understand the reason for (something)


fath·​om | \ ˈfa-t͟həm How to pronounce fathom (audio) \

Kids Definition of fathom

 (Entry 1 of 2)

: a unit of length equal to six feet (about 1.8 meters) used chiefly in measuring the depth of water


fathomed; fathoming

Kids Definition of fathom (Entry 2 of 2)

1 : to understand the reason for something I couldn't fathom how he escaped punishment.
2 : to measure the depth of water by means of a special line

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