Share this entry

fathom Line breaks: fathom
Pronunciation: /ˈfað(ə)m/

Definition of fathom in English:


A unit of length equal to six feet (1.8 metres), chiefly used in reference to the depth of water: sonar says that we’re in eighteen fathoms
More example sentences
  • If your boat is in the water and cannot be trailered, move it offshore to waters over 200 fathoms deep as soon as a Tsunami Warning is declared.
  • He is still miles and fathoms and nautical miles and light years ahead of everyone else in baseball.
  • On March 23, 1875, 13 days after leaving Nares Harbor, soundings indicated a depth of 4,475 fathoms or about 27,000 feet.


[with object] Back to top  
1 [usually with negative] Understand (a difficult problem or an enigmatic person) after much thought: the locals could not fathom out the reason behind his new-found prosperity [with clause]: he couldn’t fathom why she was being so anxious
More example sentences
  • I just can't fathom people who could have a quiet life, who don't have to be controversial for a living, but do it anyway.
  • You can analyze a Mozart piano concerto note by note and still not fathom the genius of the whole piece.
  • But I can't fathom anyone reading stories like this and not feeling the sting and burn of utter, abject shame.
interpret, decipher, decode, disentangle, untangle, unravel, piece together
informal make head or tail of, take on board, get a fix on, get/catch the drift of, tumble to, crack, dig, get, get the picture, get the message, see what's what
British informal twig, suss (out)
North American informal savvy
rare cognize
2Measure the depth of (water): an attempt to fathom the ocean
More example sentences
  • In the middle of this temple complex, there is an ancient pond, fed by the waters sprouting from its bed; it has been claimed that the depth of this pond has never been fathomed.
measure the depth of, sound, plumb, probe;
gauge, estimate


Old English fæthm, of Germanic origin; related to Dutch vadem, vaam and German Faden 'six feet'. The original sense was 'something which embraces', (plural) 'the outstretched arms'; hence, a unit of measurement based on the span of the outstretched arms, later standardized to six feet.



Pronunciation: /ˈfað(ə)məb(ə)l/
Example sentences
  • It was her view that you couldn't fathom policy until the policymakers were made fathomable.
  • Such developments may initially be unusable, only fathomable to geeks.
  • Less fathomable are his attempts to justify his growing disenchantment with the job.

Words that rhyme with fathom

rhythm • biorhythm

Definition of fathom in:

Share this entry


What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day innocuous
Pronunciation: ɪˈnɒkjʊəs
not harmful or offensive