Word.ws English Dictionary

fast

/fɑːst//fæst/

fast adjective: firmly or securely fixed in place; stable. Also the ellipsis of stand fast.

Adjective (1)

fast (comparative faster, superlative fastest)

  1. (dated) Firmly or securely fixed in place; stable.
    • That rope is dangerously loose. Make it fast!
    Antonyms:
    loose
  2. Firm against attack; fortified by nature or art; impregnable; strong.
    • out-lawes […] lurking in woods and fast places1596 (date written; published 1633), Edmund Spenser, A Vewe of the Present State of Irelande […], Dublin: […] Societie of Stationers, […], →OCLC; republished as A View of the State of Ireland […]...
    Antonyms:
    penetrable, weak
  3. Steadfast, with unwavering feeling. (Now mostly in set phrases like fast friend(s).)
    • I still hear you sayin', "Dear one, hold me fast"1933, Will Hudson, Irving Mills, Eddy DeLange, Moonglow
  4. Moving with great speed, or capable of doing so; swift, rapid; light.
    • I am going to buy a fast car.
    Synonyms:
    quick, speedy, light
    1. (nuclear physics) Having a kinetic energy between 1 million and 20 million electron volts; often used to describe the energy state of free neutrons at the moment of their release by a nuclear fission or nuclear fusion reaction (i.e., before the neutrons have been slowed down by anything).
      • Plutonium-240 has a much higher fission cross-section for fast neutrons than for thermal neutrons.
  5. Of a place, characterised by business, hustle and bustle, etc.
    • Sydney is a fast city, and the pace is becoming increasingly more frantic.1968, Carl Ruhen, The Key Club, Sydney: Scripts, page 15
  6. Causing unusual rapidity of play or action.
    • a fast racket, or tennis court
    • a fast track
  7. Able to transfer data in a short period of time.
    • But at the microlevel it consists of an unimaginable number of atoms connected by springy chemical bonds, all jiggling around at a rate that even our fastest supercomputer might envy.2007 November 18, Jim Holt, “Mind of a Rock”, in The New York Times
    Synonyms:
    quick, rapid, speedy, swift, easy
  8. Deep or sound (of sleep); fast asleep (of people).
    • Since his majesty went into the field, I have seen her rise from her bed, throw her nightgown upon her, unlock her closet, take forth paper, fold it, write upon’t, read it, afterwards seal it, and again return to bed; yet all this while in a most fast sleep.c. 1606 (date written), William Shakespeare, “The Tragedie of Macbeth”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount...
    Synonyms:
    deep, sound
    Antonyms:
    light
  9. Not running or fading when subjected to detrimental conditions such as wetness or intense light; permanent.
    • All the washing has come out pink. That red tee-shirt was not fast.
    • Mineral pigments were probably the first materials used for dyeing. They were generally not fast to water.1979, Kax Wilson, A History of Textiles, Westview Press, →ISBN, page 87
    Synonyms:
    colour-fast
  10. (obsolete) Tenacious; retentive.
    • Roses, damask and red, are fast flowers of their smells.1625, Francis [Bacon], “Of Gardens”, in The Essayes […], 3rd edition, London: […] Iohn Haviland for Hanna Barret, →OCLC
  11. (dated) Having an extravagant lifestyle or immoral habits.
    • a fast woman
    • […] we remember once hearing a fast man suggest that they were evidently "nobs who had overdrawn the badger by driving fast cattle, and going it high" — the exact signification of which words we did not understand […]1852, John Swaby, Physiology of the Opera, page 74
  12. (dated, offensive, vernacular) Uncharacteristically mature or promiscuous for one's age.
    • […] if she is of the slightly faster kind that gives smart lunch parties at the Strand Corner House, her diet is sometimes a little stronger; she takes to novels of the orchid house and the tiger's lair, to the artless erotics of Miss Elinor Glyn, Mr Hubert Wales, and Miss Victoria Cross.1918, Walter Lionel George, A Novelist on Novels
  13. Ahead of the correct time or schedule.
    • There must be something wrong with the hall clock. It is always fast.
    Synonyms:
    ahead, gain
    Antonyms:
    behind, slow
  14. More sensitive to light than average.

Noun (1)

fast (plural fasts)

  1. (UK) A train that calls at only some stations it passes between its origin and destination, typically just the principal stations.
    Synonyms:
    express, express train, fast train

Adverb

fast (comparative faster, superlative fastest)

  1. In a firm or secure manner, securely; in such a way as not to be moved; safe, sound .
    • Hold this rope as fast as you can.
    • Do as I bid you, ſhut doores after you,
      Faſt binde, faſt finde,
      A Prouerbe neuer ſtale in thrifty minde.c. 1596–1598 (date written), W[illiam] Shakespeare, The Excellent History of the Merchant of Venice. […] (First Quarto), [London]: […] J[ames] Roberts [for Thomas Heyes], published 1600, →OCLC, [Act...
    Antonyms:
    loosely
  2. Deeply or soundly .
    • The princess was sleeping fast, and her servants were fast asleep too.
    Synonyms:
    deeply
    Antonyms:
    lightly
  3. Immediately following in place or time; close, very near .
    • The horsemen came fast on our heels.
    • Fast by the sturdy batsman the ball unheeded sped. / That ain't my style, said Casey. Strike one, the umpire said.
  4. Quickly, with great speed; within a short time .
    • Do it as fast as you can.
    • Faster than a speeding bit, the internet upended media and entertainment companies. Piracy soared, and sales of albums and films slid. Newspapers lost advertising and readers to websites. Stores selling books, CDs and DVDs went bust. Doomsayers predicted that consumers and advertisers would abandon...2013 August 17, “Pennies streaming from heaven”, in The Economist, volume 408, number 8849
    Antonyms:
    slowly
  5. Ahead of the correct time or schedule.
    • I think my watch is running fast.
    Synonyms:
    ahead
    Antonyms:
    behind

Verb

fast (third-person singular simple present fasts, present participle fasting, simple past and past participle fasted)

  1. (intransitive) To practice religious abstinence, especially from food.
    • Thou didst fast and weep for the child.1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, 2 Samuel 12:21
    • Fasting he went to sleep, and fasting waked.1671, John Milton, “The First Book”, in Paradise Regain’d. A Poem. In IV Books. To which is Added, Samson Agonistes, London: […] J[ohn] M[acock] for John Starkey […], →OCLC, page 2
  2. (intransitive) To reduce or limit one's nutrition intake for medical or health reasons, to diet.
    • The ideal would be to fast in a situation where you are not tempted by food1977, Suza Norton, “To get the most benefit from fasting use a body-building diet”, in Yoga Journal, Jul-Aug 1977, p. 40
    • After the equilibration period, the rats designated for deprivation studies were made to fast for 24, 48, 72, or 96 hr according to experimental design.1983, Experimental Lung Research, volumes 5-6, Informa healthcare, page 134
  3. (transitive) To cause (a person or animal) to abstain, especially from eating.
    • At 11 weeks of age, all mice were fasted overnight and underwent gallbladder ultrasonography to determine ejection fraction.Walker et al. (2007)
    • Kittens, when fasted overnight, were not hypoglycemic (<60 mg/dl).Semick et al. (2018)

Noun (2)

fast (plural fasts)

  1. The act or practice of fasting, religious abstinence from food.
    • And is it not the Command of Christ, that in their Fast they should not appear unto men to fast?1677 George Fox, The Hypocrites Fast and Feast Not God's Holy Day, p. 8 (paraphrasing Matthew 6:16-18).
    • anciently a change of diet was not reckoned a fast; but it consisted in a perfect abstinence from all sustenance for the whole day till evening.1878, Joseph Bingham, The Antiquities of the Christian Church, volume 2, page 1182
  2. Any of the fasting periods in the liturgical year.
    • And so may we enter the Fasts at hand, beginning Lent the 30th. day of the Month Mechir1662 Peter Gunning, The Holy Fast of Lent Defended Against All Its Prophaners: Or, a Discourse, Shewing that Lent-Fast was First Taught the World by the Apostles (1677 [1662]), p. 13 (translation of...

Noun (3) capitalized: FAST

FAST (countable and uncountable, plural FASTs)

  1. (abbreviation, acronym) Acronym of focused assessment with sonography for trauma.
  2. (abbreviation, acronym) Acronym of firefighter assist and search team.
  3. (abbreviation, acronym) Acronym of free advertising-supported streaming television

Phrase capitalized: FAST

FAST

  1. (abbreviation, acronym) Acronym of facial drooping, arm weakness, speech difficulty, time, a mnemonic for diagnosing a CVA or stroke.

Proper noun (1) capitalized: FAST

FAST

  1. (abbreviation, initialism) Initialism of Five-hundred-meter Aperture Spherical Telescope.

Adjective (2) capitalized: FAST

FAST (not comparable)

  1. (abbreviation, acronym, mnemonic) An acronym for remembering desirable characteristics for goal-setting: frequently discussed, ambitious, specific, transparent.
    • What’s more, FAST goals work well across a wide range of industries. Technology companies such as Google, Intuit, and Netflix use an approach called objectives and key results (OKRs) to put these principles into action. FAST goals are also used in companies in more traditional industries, including...2018 June 5, Charles Sull and Donald Sull, “With Goals, FAST Beats SMART”, in MIT Sloan Management Review, archived from the original on 19 Aug 2018

Proper noun (2) capitalized: Fast

Fast (plural Fasts)

  1. A surname.

Also used as

fast is also the ellipsis of stand fast.

fast meaning in Hindi, Tamil, Urdu and Bengali

fast in Hindi

moving or capable of moving with great speed
तेज़ tez, तीव्र tīvra
with great speed
झटपट jhaṭpaṭ, जल्दी से jaldī se, शीघ्र śīghra
to abstain from food
व्रत vrat, उपवास करना upvās karnā, व्रत रखना vrat rakhnā

fast in Tamil

moving or capable of moving with great speed
வேகமான vēkamāṉa
to abstain from food
நோன்பிரு nōṉpiru

fast in Urdu

moving or capable of moving with great speed
تیز tez, جلد jald, تند tund, سریع sarī, عجول ajūl, عاجل ājil
to abstain from food
روزہ roza

fast in Bengali

moving or capable of moving with great speed
দ্রুত druto
to abstain from food
উপবাস রাখা upobaś rakha, উপোস করা upōs kora, রোজা রাখা rōja rakha
More languagesFewer languages
fast in Telugu
త్వరగా tvaragā, ఉపవాసం upavāsaṁ
fast in Sanskrit
आशु āśu, रघु raghu, जव java, ऋज्र ṛjra
fast in Assamese
বেগাই begai, খৰকৈ khorkoi
fast in Nepali
तेज tej, छिटो chiṭo, द्रुत drut, तीव्र tīwra
fast in Tagalog
mabilis
fast in Arabic
سَرِيع sarīʕ, سريع sarīʕ, عميق, بِسُرْعَة bi-surʕa
fast in Malay
laju, lena, puasa, berpuasa
fast in Indonesian
cepat, puasa
fast in Persian
تند tond, فرز ferz, تیز tiz, روزه گرفتن ruze gereftan
fast in Thai
เร็ว reo, ไว wai, อดอาหาร òt aahăan
fast in Vietnamese
mau, nhanh, lẹ, chóng
fast in Myanmar
မြန် mran
Kashmiri
فاقہٕ تھَوُن fāqhụ thavun, ورَٛتھ تھَوُن, روزٕ تھَوُن rōzụ thavun, وۄپَس دیُٛن

Examples of fast in a sentence

  • a fast billiard table
  • Cochineal is remarkably fast on protein fibers, remaining brilliant and saturated despite exposure to sunlight and washing.2026, Sara Temme, “Two Insects nad Their Brilliant Reds”, in Handwoven, volume XLVII, number 1, page 19:
  • “I don’t like that young woman,” said Lady Hermione; she’s fast.” “Dear Lady!” “I’ve no doubt you think me old-fashioned.1933, Dorothy L. Sayers, The Queen’s Square:
  • You're alone with her at last / And you're waiting 'til you think the time is right / Cause you've heard she's pretty fast / And you're hoping that she'll give you some tonight.1979, Doug Fieger, Good Girls Don't:
  • Faster than a speeding bit, the internet upended media and entertainment companies.2013 August 17, “Pennies streaming from heaven”, in The Economist, volume 408, number 8849:

All 40 example sentences with fast

Synonyms of fast

22 more synonymsFewer synonyms

Antonyms

2 more antonymsFewer antonyms

All synonyms and antonyms of fast

Forms of fast

Adjective
comparativefaster
superlativefastest
Noun
pluralfasts
pluralFASTs
alternative formfast
alternative formFast
alternative formF.A.S.T.
alternative formF. A. S. T.
Adverb
comparativefaster
superlativefastest
Verb
third-person singular presentfasts
present participlefasting
past participlefasted
pastfasted
Proper noun
pluralFasts

Past tense of fast: fasted

Plural of fast: fasts

Origin of fast

From Middle English fast, fest, from Old English fæst (“firm, secure”), from Proto-West Germanic *fast, from Proto-Germanic *fastuz; see it for cognates and further etymology. The development of “rapid” from an original sense of “secure” apparently happened first in the adverb and then transferred to the adjective; compare hard in expressions like “to run hard”. The original sense of “secure, firm” is now slightly archaic, but retained in the related fasten (“make secure”). Also compare close meaning change from Latin rapiō (“to snatch”) to Latin rapidus (“rapid, quick”), from Irish sciob (“to snatch”) to Irish sciobtha (“quick”).

From Middle English fast, faste, from Old English fæste, from fæst + -e (adverb-forming suffix).

From Middle English fasten, from Old English fæstan (“to fast”), from Proto-West Germanic *fastēn, from Proto-Germanic *fastāną (“to fast”), from the same root as Proto-Germanic *fastijaną (“to fasten”), derived from *fastuz, and thereby related to Etymology 1. The religious sense is presumably introduced in the Gothic church, from Gothic 𐍆𐌰𐍃𐍄𐌰𐌽 (fastan, “hold fast (viz. to the rule of abstinence)”). This semantic development is unique to Gothic, the term glosses Greek νηστεύω (nēsteúō), Latin ieiuno which do not have similar connotations of "holding fast". The feminine noun Old High German fasta likely existed in the 8th century (shift to neuter Old High German fasten from the 9th century, whence modern German Fasten). The Old English noun originally had the sense "fortress, enclosure" and takes the religious sense only in late Old English, perhaps influenced by Old Norse fasta. The use for reduced nutrition intake for medical reasons or for weight reduction develops by the mid-1970s, back-formed from the use of the verbal noun fasting in this sense (1960s).

Words formed from fast

Phrases with fast

100 more phrasesFewer phrases

Words that rhyme with fast

4 more rhymesFewer rhymes

Questions about fast

What does fast mean?
Fast means firmly or securely fixed in place; stable.
What is fast in Hindi?
Fast in Hindi is तेज़ (tez), तीव्र (tīvra), झटपट (jhaṭpaṭ). See Fast meaning in Hindi.
How do you use fast in a sentence?
a fast billiard table
What part of speech is fast?
Fast can be an adjective, a noun, an adverb or a verb.
How do you pronounce fast?
Fast is pronounced /fɑːst/ (UK).

Words near fast in the dictionary

  1. Fassifern
  2. Fassler
  3. Fasslers
  4. Fassnacht
  5. Fassnachts
  6. fast
  7. fast and furious
  8. fast and loose
  9. fast as lightning
  10. fast asleep
  11. fast backward

Source and license

Adapted from Wiktionary: fast (page history and authors); FAST (page history and authors); Fast (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Pronunciation audio from Wikimedia Commons, each file under its own free license: en-uk-fast.ogg, en-us-fast.ogg.

Cite this entry: “fast.” Word.ws, https://word.ws/fast. Based on Wiktionary, CC BY-SA 4.0.