# fathom

> English word · Noun · IPA /ˈfað(ə)m/ · frequency rank #20,922

## Definitions
1. 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.
2. 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.
3. A measure of distance to shore: the nearest point to shore at which the water depth is the value quoted.
4. An unspecified depth.
5. Depth of insight; mental reach or scope.
6. 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.
7. Someone or something that is embraced.
8. Control, grasp.

## Etymology
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], 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”).
Cognates
* Ancient Greek πέταλος (pétalos, “broad; flat”), πετᾰ́ννῡμῐ (petắnnūmĭ, “to open; to spread out; to be dispersed or scattered”) (whence English petal)
* Gothic 𐍆𐌰𐌸𐌰 (faþa, “fench; hedge”)
* Latin pateō (“to extend, increase; to be accessible, attainable, open; to be exposed, vulnerable”)
* Low German fadem, faem (“cubit; thread”)
* Middle Dutch vadem (modern Dutch vaam, vadem (“fathom”))
* Norwegian Bokmål favn (“an embrace; a fathom”)
* Old Frisian fethm (“outstretched arms”)
* Old High German fadam, fadum (“cubit”) (Middle High German vade (“enclosure”), vadem, vaden, modern German Faden (“fathom; filament, thread”))
* Old Norse faþmr (Danish favn (“an embrace; a fathom”), Icelandic faðmur (“an embrace”), Swedish famn (“the arms, bosom; an embrace”))
* Old Welsh etem (“thread”)

## Easily confused with
- **father** (https://plainspell.com/en/vs/father-vs-fathom)
- **fandom** (https://plainspell.com/en/vs/fandom-vs-fathom)

## Common misspellings (9)
`afthom`, `fahtom`, `fathhom`, `fathmo`, `fathomm`, `fatohm`, `fatthom`, `ffathom`, `ftahom`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/fathom