fathom

Etymology

From Middle English fathome, fadome, from Old English fæþm, fæþme (“outstretched or encircling arms, embrace, grasp, protection, interior, bosom, lap, breast, womb, fathom, cubit, power, expanse, surface”), from Proto-Germanic *faþmaz (“embrace”), from Proto-Indo-European *pet- (“to spread out, extend”). Cognate with Low German fadem, faem (“a cubit, thread”), Dutch vadem, vaam (“fathom”), German Faden (“thread, filament, fathom”), Danish favn (“embrace, fathom”), Swedish famn (“the arms, bosom, embrace”), Icelandic faðmur (“embrace”), Latin pateō, Ancient Greek πετάννυμι (petánnumi).

Pronunciation

• IPA^(key): /ˈfæðəm/

• Audio (US)

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Noun

fathom (plural fathoms)

1. (obsolete) Grasp, envelopment, control.
2. (units of measure, now usually nautical) An English unit of length for water depth notionally based upon the width of grown man's outstretched arms but standardized as 6 feet (about 1.8 m)
3. (units of measure) Various similar units in other systems.
4. (figuratively) Depth of insight, mental reach or scope.
   • Shakespeare, Othello, Act I, Scene i, ll. 151-2:

     Another of his fathom they have none
     To lead their business.

Verb

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

1. (transitive, archaic) To encircle with outstretched arms, especially to take a measurement; to embrace.
2. (transitive) To measure the depth of, take a sounding of.
3. (transitive, figuratively) To get to the bottom of; to manage to comprehend; understand (a problem etc.).

   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)‎:

     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.

Related terms

• fathomable
• fathometer
• fathomless
• fathom out
• unfathomable

Further reading

• fathom in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
• fathom in The Century Dictionary, The Century Co., New York, 1911
• fathom at OneLook Dictionary Search