fast

¹ American  

[fast, fahst] / fæst, fɑst /

adjective

• faster,
  comparative
• fastest
  superlative

1. moving or able to move, operate, function, or take effect quickly; quick; swift; rapid: a fast pain reliever;

   a fast horse;

   a fast pain reliever;

   a fast thinker.

   Synonyms:

   speedy, fleet

   Antonyms:

   slow

2. done in comparatively little time; taking a comparatively short time: fast work.

   a fast race;

   fast work.

   Synonyms:

   speedy, fleet

   Antonyms:

   slow

3. (of time)

   1. indicating a time in advance of the correct time, as of a clock.

   2. noting or according to daylight-saving time.

4. adapted to, allowing, productive of, or imparting rapid movement: one of the fastest pitchers in baseball.

   a hull with fast lines;

   one of the fastest pitchers in baseball.

5. characterized by unrestrained conduct or lack of moral conventions, especially in sexual relations; wanton; loose.

   Some young people in that era were considered fast, if not downright promiscuous.

   Synonyms:

   prodigal, wild, immoral, profligate, dissolute, dissipated

   Antonyms:

   restrained

6. characterized by hectic activity.

   leading a fast life.

   Antonyms:

   restrained

7. resistant.

   acid-fast.

8. firmly fixed in place; not easily moved; securely attached.

   Synonyms:

   firm, immovable, tight, secure

   Antonyms:

   loose

9. held or caught firmly, so as to be unable to escape or be extricated.

   an animal fast in a trap.

   Synonyms:

   inextricable

10. firmly tied, as a knot.

11. closed and made secure, as a door, gate, or shutter.

12. such as to hold securely.

    to lay fast hold on a thing.

13. firm in adherence; loyal; devoted.

    fast friends.

    Synonyms:

    steadfast, faithful

14. permanent, lasting, or unchangeable: a hard and fast rule.

    a fast color;

    a hard and fast rule.

    Synonyms:

    enduring

15. Informal.

    1. (of money, profits, etc.) made quickly or easily and sometimes deviously.

       He earned some fast change helping the woman with her luggage.

    2. cleverly quick and manipulative in making money.

       a fast operator when it comes to closing a business deal.

16. Photography.

    1. (of a lens) able to transmit a relatively large amount of light in a relatively short time.

    2. (of a film) requiring a relatively short exposure time to attain a given density.

17. Horse Racing.

    1. (of a track condition) completely dry.

    2. (of a track surface) very hard.

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adverb

faster, fastest

1. quickly, swiftly, or rapidly.

2. in quick succession.

   Events followed fast upon one another to the crisis.

3. tightly; firmly.

   to hold fast.

   Synonyms:

   tenaciously, fixedly, securely

4. soundly.

   fast asleep.

5. in a wild or dissipated way.

   Synonyms:

   prodigally, wildly, recklessly

6. ahead of the correct or announced time.

7. Archaic. close; near.

   fast by.

noun

1. a fastening for a door, window, or the like.

idioms

1. pull a fast one, to play an unfair trick; practice deceit.

   He tried to pull a fast one on us by switching the cards.

2. play fast and loose. play.

fast ² American  

[fast, fahst] / fæst, fɑst /

verb (used without object)

• fasts,
  present (3rd person singular)
• fasted,
  past participle,  past
• fasting
  present participle

1. to abstain from all food.

2. to eat only sparingly or of certain kinds of food, especially as a religious observance.

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verb (used with object)

• fasts,
  present (3rd person singular)
• fasted,
  past participle,  past
• fasting
  present participle

1. to cause to abstain entirely from or limit food; put on a fast.

   to fast a patient for a day before surgery.

noun

1. an abstinence from food, or a limiting of one's food, especially when voluntary and as a religious observance; fasting.

2. a day or period of fasting.

fast ³ American  

[fast, fahst] / fæst, fɑst /

noun

1. a chain or rope for mooring a vessel.

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fast ¹ British  

/ fɑːst /

adjective

1. acting or moving or capable of acting or moving quickly; swift

2. accomplished in or lasting a short time

   fast work

   a fast visit

3. (prenominal) adapted to or facilitating rapid movement

   the fast lane of a motorway

4. requiring rapidity of action or movement

   a fast sport

5. (of a clock, etc) indicating a time in advance of the correct time

6. given to an active dissipated life

7. of or characteristic of such activity

   a fast life

8. not easily moved; firmly fixed; secure

9. firmly fastened, secured, or shut

10. steadfast; constant (esp in the phrase fast friends )

11. sport (of a playing surface, running track, etc) conducive to rapid speed, as of a ball used on it or of competitors playing or racing on it

12. that will not fade or change colour readily

    a fast dye

13. 1. proof against fading

       the colour is fast to sunlight

    2. ( in combination )

       washfast

14. photog

    1. requiring a relatively short time of exposure to produce a given density

       a fast film

    2. permitting a short exposure time

       a fast shutter

15. cricket (of a bowler) characteristically delivering the ball rapidly

16. informal glib or unreliable; deceptive

    a fast talker

17. archaic sound; deep

    a fast sleep

18. informal a deceptive or unscrupulous trick (esp in the phrase pull a fast one )

19. a person who achieves results quickly, esp in seductions

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adverb

1. quickly; rapidly

2. soundly; deeply

   fast asleep

3. firmly; tightly

4. in quick succession

5. in advance of the correct time

   my watch is running fast

6. in a reckless or dissipated way

7. archaic close or hard by; very near

8. informal to behave in an insincere or unreliable manner

interjection

1. archery (said by the field captain to archers) stop shooting!

fast ² British  

/ fɑːst /

verb

1. (intr) to abstain from eating all or certain foods or meals, esp as a religious observance

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noun

1. 1. an act or period of fasting

   2. ( as modifier )

      a fast day

fast More Idioms  

More idioms and phrases containing fast

• get nowhere (fast)
• hard and fast
• pull a fast one
• stand one's ground (fast)
• thick and fast

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Synonym Usage

See quick.

Other Word Forms

Derived Forms

• faster
  noun
• unfasting
  adjective

Inflected Forms

Adjectives

• faster
  comparative
• fastest
  superlative

Participles

• fasting
  present
• fasted
  past

Conjugated Forms

Present

• fast
  simple
• fasts
  simple
• have fasted
  perfect
• has fasted
  perfect
• am fasting
  progressive
• are fasting
  progressive
• is fasting
  progressive
• have been fasting
  perfect progressive
• has been fasting
  perfect progressive

Past

• fasted
  simple
• had fasted
  perfect
• was fasting
  progressive
• were fasting
  progressive
• had been fasting
  perfect progressive

Future

• will fast
  simple
• will have fasted
  perfect
• will be fasting
  progressive
• will have been fasting
  perfect progressive

Etymology

Origin of fast¹

First recorded before 900; Middle English; Old English fæst “firm”; cognate with Dutch vast, Old Norse fastr “firm,” German fest; akin to fast ²

Origin of fast²

First recorded before 1000; Middle English fasten, festen, Old English fæstan; cognate with German fasten, Gothic fastan, Old Norse fasta

Origin of fast³

First recorded in 1670–80; alteration, by association with fast ¹ ( def. ) (in the sense “firmly tied”), of late Middle English fest “fastening, mooring rope,” from Old Norse festr “mooring rope, cable,” from Old Norse fastr “fixed, firm”; cf. fasten, fast ¹

Explanation

When you see fast, you might think of Olympic runner Usain "Lightning" Bolt or a Porsche 911 Turbo. Alternatively, and quite confusingly, fast also means to refrain from eating for a certain period, usually for religious reasons. Fast is another of those deceptively simple words that have a number of other meanings beyond their most common usages. If something "sticks fast" it means it cannot be removed — like a leech or a stain. "To stand fast" means not to give up your point of view or to remain loyal. Then there's also the slang meaning of living beyond the constraints of normal behavior — as in "the fast life," "the fast track," or "the fast lane."

Example Sentences

See Examples For:

fast faster fastest fasts fasted fasting

This measurement reflects the amount of sugar in the blood after an eight- to 12-hour fast.

From Science Daily ● Aug. 16, 2026

“You got to go fast and get the quarterback before he passes. You got about three seconds.”

From Los Angeles Times ● Aug. 16, 2026

The future was coming on fast, and it was dumb as a brick.

From Salon ● Aug. 16, 2026

A spokesman for McDonald’s fraud division said it is “expanding fast, securing more resources and here to stay—relentlessly hunting every fraudster who steals from the American people.”

From The Wall Street Journal ● Aug. 14, 2026

I sat up, half raised, afraid to move fast lest she panic and run back into the wolves.

From "Woodsong" by Gary Paulsen

She realized that to even make the U.S. team for Paris, she needed to swim faster with one leg than she did with two.

From Los Angeles Times ● Aug. 16, 2026

“It searches much faster than we can across many more spaces,” said Peng, who is director of advanced diagnostics and therapeutics at the New York Center for Rare Diseases.

From The Wall Street Journal ● Aug. 15, 2026

But as inequality has supercharged the gap between workers with the highest and lowest incomes, wages above the cap have grown much faster than those under the cap, Romig noted.

From MarketWatch ● Aug. 14, 2026

But Germany's Ansah matched that with a personal-best run in the semi-finals, before going faster still in the final, as British record-holder Hughes took silver in 20.16.

From BBC ● Aug. 14, 2026

It didn’t make the raft go much faster, but Alex felt better doing something.

From "Nim’s Island" by Wendy Orr

The SHO made its debut in 1989 as the fastest front-wheel-drive car in the world.

From The Wall Street Journal ● Aug. 16, 2026

It follows a 0.6% rise in the first quarter—the fastest among the Group of 7 leading industrialized nations.

From The Wall Street Journal ● Aug. 13, 2026

Before the race, there were hopes of a British one-two-three on the podium, with Asher-Smith, Hunt and Success Eduan holding the three fastest times in Europe times this year.

From BBC ● Aug. 13, 2026

Werro - who ran the fastest time for 43 years earlier this season - led from the start in the first semi-final, but crashed to the floor on the final bend.

From BBC ● Aug. 13, 2026

A single pink boot, all shiny like candy, one of the fastest boots in the world, real nishin.

From "The Marrow Thieves" by Cherie Dimaline

By one estimate, Gandhi undertook at least 15 major fasts.

From BBC ● Jul. 16, 2026

Still, scientists have had only a limited understanding of exactly how the body responds during longer fasts.

From Science Daily ● May 17, 2026

Six Flags Qiddiya City recently hosted iftar celebrations that marked the end of the daily Ramadan fasts.

From The Wall Street Journal ● Mar. 26, 2026

Bonta, who intermittently fasts and tries not to eat before noon, was sticking to black coffee.

From Los Angeles Times ● Feb. 19, 2025

He was a silent, brooding man, given to fasts and contemplation, going often, alone, into the caves of the mountains, in the section of Virginia where he lived.

From "Harriet Tubman: Conductor on the Underground Railroad" by Ann Petry

Wangchuk fasted in scorching heat in the capital, Delhi, for 26 days in June and July, consuming only salt and water.

From BBC ● Aug. 5, 2026

He said that he did go to the mosque every Friday, and that he prayed and fasted and raised his children to be good Muslims.

From Slate ● Apr. 19, 2026

These individuals typically ate their first meal after 14:00 and fasted for about 17 hours.

From Science Daily ● Apr. 11, 2026

In came the resistance bands, dead lifts, dumbbells and agility drills, plus a private chef who got a sweet break from 8 p.m. until noon the next day, as Doncic intermittently fasted.

From The Wall Street Journal ● Sep. 16, 2025

Instead she fasted or ate vegetarian meals in her room.

From "The Joy Luck Club" by Amy Tan

In late 2022, Elon Musk posted that he lost 30 pounds by fasting and taking semaglutide.

From MarketWatch ● Aug. 5, 2026

It is the fasting warming content, heating up twice as fast as the global average, according to the Copernicus climate service.

From BBC ● Jul. 30, 2026

At the protest site in the capital Delhi, he began fasting on 28 June and has consumed nothing but salt and water since then, losing more than 9kg.

From BBC ● Jul. 20, 2026

According to the research team, even a 12 week period of intermittent fasting could provide an effective medium term option for weight management among adults who are overweight or obese.

From Science Daily ● Jul. 18, 2026

And how he does it while fasting on Mondays and Fridays—he’s become more religious—is beyond her.

From "Zeitoun" by Dave Eggers

Related Words

• agile
• brisk
• hot
• nimble
• quick
• rapid
• swift