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 fathomable (audio) \ adjective

Synonyms for fathom

Synonyms: Verb

plumb, sound

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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


The water here is five fathoms deep.


the pilot had to continually fathom the river, which drought conditions had lowered to unprecedented levels

Recent Examples on the Web: Noun

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 Twain's pen name originates from his time working with steamboats: Twain refers to a measure of length known as two fathoms (12 feet). Logan Sykes, Town & Country, "Happy 180th Birthday, Mark Twain! 16 Facts You Need to Know About The Author," 30 Nov. 2015 However, the modern dive watch dates back to the mid-1950s, when Blancpain's 50 Fathoms and Rolex's Submariner both appeared. Steve Dool, CNN, "Understated but 'never easy': Why collectors covet Patek Philippe," 18 July 2017 Time traveling below the waves Dropping 10 fathoms down, below the green waves of the Gulf and back in time to this prehistoric world amounts to a sort of time traveler's journey. Ben Raines, NOLA.com, "Gulf's 60,000-year-old underwater forest spills its secrets in new documentary," 25 June 2017

Recent Examples on the Web: Verb

It’s hard to fathom that the Wampanoag — who welcomed the Pilgrims and ate at the first Thanksgiving — could be stripped of their ability to govern land. Shirley Leung, BostonGlobe.com, "In Taunton, a gamble that has yet to pay off," 6 Apr. 2018 Bedrooms have fathoms-deep baths and a mix of antique and contemporary furniture, much of the latter commissioned for the property from makers like Don Howell and Matthew Hilton. Jo Rodgers, Condé Nast Traveler, "Inside the U.K.'s Most Anticipated Hotel Opening This Summer," 31 Aug. 2018 Four American presidents—Bill Clinton, George W. Bush, Barack Obama and now Donald Trump —have since tried to fathom his intentions and respond to his domestic and foreign-policy moves. Joshua Rubenstein, WSJ, "‘The Code of Putinism’ Review: Summing Up a Summit Partner," 15 July 2018 The effects of malicious exploits, assuming there were any during the four-plus years the bug was active, are hard to fathom. Dan Goodin, Ars Technica, "Trivial authentication bypass in libssh leaves servers wide open," 17 Oct. 2018 But that, of all the D.C. private schools, Georgetown Prep would be the one to have two graduates on the highest court in the land was something few of us could fathom. Jason Zengerle, Town & Country, "Brett Kavanaugh and the Private School Pecking Order," 16 Oct. 2018 The hotel staff can’t fathom the idea of Chinese people being able to afford their plush accommodations. Alex Abad-santos, Vox, "Crazy Rich Asians has a daring premise: an Asian man that everyone desires," 17 Aug. 2018 What would be a story beyond fathoming for the second-grade class Lieberg will teach Monday back home in Helena, Mont., became something nevertheless inspiring. Lance Pugmire, latimes.com, "L.A. Marathon: Montana teacher enjoys hanging with top runners — and finishing among top Americans," 18 Mar. 2018 Yellowstone’’ — whose June 20 premiere earned a stellar 4.8 million viewers, counting DVR, in its first three days — to reflect a culture and a mind-set that city dwellers have trouble fathoming. Scott Tobias, BostonGlobe.com, "How TV has brought the western into the 21st century," 5 July 2018

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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Statistics for fathom

Last Updated

25 Jan 2019

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Time Traveler for fathom

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

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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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