fathom

1 of 2

noun

fath·​om ˈfa-t͟həm 

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 works

—Newsweek

fathom

2 of 2

verb

fathomed; fathoming; fathoms

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

fathomable

ˈfa-t͟hə-mə-bəl 

adjective

Did you know?

Did fathom Always Refer to a Measurement?

Fathom comes from the Old English word 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 was a synonym of our modern embrace: to fathom someone was to encircle the person with your arms. By the 1600s fathom had taken to the seas, with the verb being used to mean "to measure by a sounding line." At the same time, the verb also developed senses synonymous with probe and investigate, and it is now frequently used to refer to the act of getting to the bottom of something, figuratively speaking.

Synonyms

Verb

• plumb
• scale
• span

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

This offered the benefit of drilling through less rock, but came with the challenge of operating a drill rig from a ship positioned above several thousand fathoms of open ocean. —David Szondy june 08, New Atlas, 8 June 2025

Similarly, many incompetent California politicians starting with Gov. Gavin Newsom and Los Angeles Mayor Karen Bass should have their political careers sunk 2,000 fathoms, never to rise again. —Reader Commentary, Baltimore Sun, 22 Jan. 2025

Verb

The singer can’t fathom how Nelly can sleep peacefully throughout the night while their child, Kareem Kenkaide (KK), is crying incessantly. —Mya Abraham, VIBE.com, 30 June 2025

While couples dream of hosting a big white wedding with hundreds of guests, others can’t fathom the idea and would prefer to celebrate in a much more intimate setting. —Shelby Wax, Vogue, 24 June 2025

Word History

Etymology

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

First Known Use

Noun

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

Verb

1607, in the meaning defined at intransitive sense 1

Podcast

Get Word of the Day delivered to your inbox!

Kids Definition

fathom

1 of 2 noun

fath·​om ˈfat͟h-əm 

: a unit of length equal to six feet (about 1.83 meters) used especially for measuring the depth of water

fathom

2 of 2 verb

1

: to measure by a sounding line

2

: to come to understand

can't fathom why

fathomable

ˈfat͟h-ə-mə-bəl 

adjective