What does "fathom" mean?
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.
Fathom
/ˈfað(ə)m/ noun, verb
noun, verb ·Common ·High school level
Meaning at a glance
- Primary sense: 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.
- Grammar: fathom is listed as noun, verb.
- Nearest alternatives: absorb, answer, appraise, appreciate.
- Useful contrasts: miscalculate, misestimate, misinterpret.
- Usage evidence: I can't begin to fathom how someone could believe that one race is superior to another.
How to use "fathom"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "fathom" carries the exact meaning, tone, and strength you need.
- Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.
Meaning check
- Does the word fit the sentence's grammar?
- Does it match the intended tone rather than only the dictionary definition?
- Would a simpler synonym be clearer for the reader?
- Is there enough surrounding context to prevent ambiguity?
Source and review context
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "fathom" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Before you rely on this definition
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "fathom" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "fathom" with a nearby alternative so the final choice matches both meaning and reader expectation.
Compare nearby meanings
- Use synonyms when you need a softer, stronger, simpler, or more specific word.
- Use antonyms to check the boundary of the meaning and avoid accidental contrast.
- Use the example sentence to confirm the word behaves naturally in context.
- Keep the original wording when a replacement adds complexity without improving precision.
Definition decision workflow
1. Identify the role
Check whether "fathom" is acting as noun, verb in your sentence. A definition is only useful when the grammar matches the way the word is being used.
2. Test the nearest option
Compare it with "absorb" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
3. Confirm with context
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Final meaning check
Before publishing a sentence with "fathom", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
Definitions
Noun
- 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. US, historical
"[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."
- 2 (mining) a unit of volume (equal to 6 cubic feet) used in measuring bodies of ore wordnet
- 3 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.; An internationally standardized version of this unit, the international fathom (= 1.8288 metres = 6 feet). US, historical
- 4 a linear unit of measurement (equal to 6 feet) for water depth wordnet
- 5 A measure of distance to shore: the nearest point to shore at which the water depth is the value quoted. US
"After we'd rowed for an hour, we found ourselves stranded ten fathoms from shore."
Show 5 more definitions
- 6 An unspecified depth. figuratively, in-plural
- 7 Depth of insight; mental reach or scope. archaic, figuratively, obsolete
"Another of his fathome they haue not / To leade their buſineſſe, […]"
- 8 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. obsolete
- 9 Someone or something that is embraced. obsolete
"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."
- 10 Control, grasp. figuratively, obsolete
"So; novv knovv I vvhere I am, me thinkes already / I graſpe beſt part of the Autumnian bleſſing / In my contentious fadome, […]"
Verb
- 1 To measure the depth of (water); to take a sounding of; to sound. also, figuratively, transitive
- 2 measure the depth of (a body of water) with a sounding line wordnet
- 3 To encircle (someone or something) with outstretched arms; specifically, to measure the circumference or (rare) length of something. archaic, obsolete, transitive
- 4 come to understand wordnet
- 5 Often followed by out: to deeply understand (someone or something); to get to the bottom of. figuratively, transitive
"I can’t for the life of me fathom what this means."
Show 3 more definitions
- 6 To embrace (someone or something). obsolete, transitive
- 7 To measure a depth; to sound. intransitive
- 8 To conduct an examination or inquiry; to investigate. figuratively, intransitive
Example
"I can't begin to fathom how someone could believe that one race is superior to another."
Common questions
What is a synonym for "fathom"?
Common synonyms include: absorb, answer, appraise, appreciate, apprehend, apprehend.
How do you use "fathom" in a sentence?
I can't begin to fathom how someone could believe that one race is superior to another.
How do you pronounce "fathom"?
Pronounced /ˈfað(ə)m/.
Etymology
Etymology 1
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”)
Etymology 2
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], from Old English fæðmian, from Proto-Germanic *faþmōjan, from *faþm (“outstretched arms, embrace; fathom (unit of measurement)”): see further at etymology 1. Cognates * Old High German fademōn * Old Norse faþma (Danish favne (“to embrace”), Icelandic to embrace, hug; to cuddle, Swedish famna)