fathom

• (Received Pronunciation) IPA^(key): /ˈfað(ə)m/
• (General American) IPA^(key): /ˈfæðəm/
• (dialectal, obsolete) IPA^(key): /ˈfædəm/^[1]

• Audio (General American):

  (file)

• Hyphenation: fa‧thom

From Middle English fathome, fadom, fadme (“unit of length of about six feet; depth of six feet for nautical soundings; (loosely) cubit; ell”) [and other forms],^[2] from Old English fæþm, fæþme (“encircling or outstretched arms, bosom, embrace; envelopment; control, grasp, power; fathom (unit of measurement); cubit”) [and other forms], from Proto-West Germanic *faþm (“outstretched arms, embrace; fathom (unit of measurement)”), from Proto-Germanic *faþmaz (“outstretched arms, embrace; fathom (unit of measurement)”), from Proto-Indo-European *pet-, *peth₂- (“to spread out; to fly”).^[3]

fathom (plural fathoms)

1. (chiefly nautical, historical, US) A man's armspan, generally reckoned to be six feet (about 1.8 metres). Later used to measure the depth of water, but now generally replaced by the metre outside American usage.
   • 1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, Acts 27:27–28, column 2:

     [T]he ſhipmen deemed that they drew neere to ſome countrey: And ſounded, and found it twentie fathoms: and when they had gone a little further, they ſounded againe, and found it fifteene fathoms.

   • 1610–1611 (date written), William Shakespeare, “The Tempest”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act I, scene i], page 5, column 1:

     Full fadom fiue thy Father lies,
     Of his bones are Corrall made:
     Those are pearles that were his eies,
     Nothing of him that doth fade,
     But doth suffer a Sea-change
     Into someting rich, & strange

2. (nautical, US) A measure of distance to shore: the nearest point to shore at which the water depth is the value quoted.

   After we'd rowed for an hour, we found ourselves stranded ten fathoms from shore.

   • 1983, Richard Ellis, “The Predators”, in The Book of Sharks, 1st paperback edition, New York, N.Y.: Alfred A[braham] Knopf, published 1989, →ISBN, page 7:

     At fifty fathoms, the waters of the Southern Ocean are dark blue.

3. (figuratively)
   1. (chiefly in the plural) An unspecified depth.
   2. (archaic or obsolete) Depth of insight; mental reach or scope.
      • c. 1603–1604 (date written), William Shakespeare, The Tragœdy of Othello, the Moore of Venice. […] (First Quarto), London: […] N[icholas] O[kes] for Thomas Walkley, […], published 1622, →OCLC, [Act I, scene i]:

        Another of his fathome they haue not / To leade their buſineſſe, […]

4. (obsolete)
   1. The act of stretching out one's arms away from the sides of the torso so that they make a straight line perpendicular to the body.
   2. Someone or something that is embraced.
      • 1601 (first performance), Thomas Dekker, Satiro-mastix. Or The Untrussing of the Humorous Poet. […], London: […] [Edward Allde] for Edward White, […], published 1602, →OCLC, signature E, verso:

        Thy Bride, thy choice, thy vvife, / She that is novv thy fadom, […] Kneele at thy feete, obay in euerie thing, / So euerie Father is a priuate King.

   3. (figuratively) Control, grasp.
      • 1604 (first performance), [Thomas Middleton], “Inductio”, in Michaelmas Terme. […], London: […] [Thomas Purfoot and Edward Allde] for A[rthur] I[ohnson] […], published 1607, →OCLC, signature A2, recto:

        So; novv knovv I vvhere I am, me thinkes already / I graſpe beſt part of the Autumnian bleſſing / In my contentious fadome, […]

      • 1622 May 24 (licensing date), John Fletcher, Philip Massinger, “The Prophetesse”, in Comedies and Tragedies […], London: […] Humphrey Robinson, […], and for Humphrey Moseley […], published 1647, →OCLC, Act II, scene i, page 29:

        Yes: / you have blovvne his ſvvolne pride to that vaſtnes, / as he beleeves the earth is in his fadom, / this makes him qute forget his humble Being: […]

• At sea, the fathom is exclusively a measure of water depth. Therefore, a boat that is 100 fathoms offshore is not 600 feet from the shore, but rather at the nearest point to shore where the water depth is 600 feet.

• (unit of length): stade; toise (some contexts); brace (some contexts); braza, estadio (Spanish contexts); orguia (Greek contexts)

• fathometer

• deep six

From Middle English fathmen, fadmen (“to encircle (something) with the arms, embrace; to feel, grope; to measure by the ell (or perhaps the fathom)”) [and other forms],^[4] from Old English fæðmian, from Proto-Germanic *faþmōjan, from *faþm (“outstretched arms, embrace; fathom (unit of measurement)”):^[5] see further at etymology 1.

fathom (third-person singular simple present fathoms, present participle fathoming, simple past and past participle fathomed)

1. (transitive)
   1. (also figurative) To measure the depth of (water); to take a sounding of; to sound.
   2. (archaic or obsolete) To encircle (someone or something) with outstretched arms; specifically, to measure the circumference or (rare) length of something.
   3. (figurative) Often followed by out: to deeply understand (someone or something); to get to the bottom of.

      Synonyms: figure out, puzzle out, work out

      Coordinate term: grok

      I can’t for the life of me fathom what this means.

      • 2018 April 10, Daniel Taylor, “Liverpool go through after Mohamed Salah stops Manchester City fightback”, in The Guardian (London)‎^[2]:

        Otamendi’s selection ahead of Vincent Kompany was difficult to fathom and, apart from Fernandinho, City’s line-up was otherwise filled with attacking players.

   4. (obsolete) To embrace (someone or something).
2. (intransitive)
   1. To measure a depth; to sound.
   2. (figurative) To conduct an examination or inquiry; to investigate.

• fathom on Wikipedia.Wikipedia
• fathom (disambiguation) on Wikipedia.Wikipedia
• “fathom”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.
• “fathom”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “fathom”, in OneLook Dictionary Search.