fast
1 Americanadjective
-
faster,
comparative
-
fastest
superlative
-
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.
- Antonyms:
- slow
-
done in comparatively little time; taking a comparatively short time: fast work.
a fast race;
fast work.
- Antonyms:
- slow
-
(of time)
-
indicating a time in advance of the correct time, as of a clock.
-
noting or according to daylight-saving time.
-
-
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.
-
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
-
characterized by hectic activity.
leading a fast life.
- Antonyms:
- restrained
-
resistant.
acid-fast.
-
firmly fixed in place; not easily moved; securely attached.
- Antonyms:
- loose
-
held or caught firmly, so as to be unable to escape or be extricated.
an animal fast in a trap.
- Synonyms:
- inextricable
-
firmly tied, as a knot.
-
closed and made secure, as a door, gate, or shutter.
-
such as to hold securely.
to lay fast hold on a thing.
-
firm in adherence; loyal; devoted.
fast friends.
-
permanent, lasting, or unchangeable: a hard and fast rule.
a fast color;
a hard and fast rule.
- Synonyms:
- enduring
-
Informal.
-
(of money, profits, etc.) made quickly or easily and sometimes deviously.
He earned some fast change helping the woman with her luggage.
-
cleverly quick and manipulative in making money.
a fast operator when it comes to closing a business deal.
-
-
Photography.
-
(of a lens) able to transmit a relatively large amount of light in a relatively short time.
-
(of a film) requiring a relatively short exposure time to attain a given density.
-
-
Horse Racing.
-
(of a track condition) completely dry.
-
(of a track surface) very hard.
-
adverb
-
quickly, swiftly, or rapidly.
-
in quick succession.
Events followed fast upon one another to the crisis.
-
to hold fast.
- Synonyms:
- tenaciously, fixedly, securely
-
fast asleep.
-
in a wild or dissipated way.
- Synonyms:
- prodigally, wildly, recklessly
-
ahead of the correct or announced time.
-
Archaic. close; near.
fast by.
noun
idioms
-
pull a fast one, to play an unfair trick; practice deceit.
He tried to pull a fast one on us by switching the cards.
-
play fast and loose. play.
verb (used without object)
-
fasts,
present (3rd person singular)
-
fasted,
past participle, past
-
fasting
present participle
-
to abstain from all food.
-
to eat only sparingly or of certain kinds of food, especially as a religious observance.
verb (used with object)
-
fasts,
present (3rd person singular)
-
fasted,
past participle, past
-
fasting
present participle
noun
-
an abstinence from food, or a limiting of one's food, especially when voluntary and as a religious observance; fasting.
-
a day or period of fasting.
noun
adjective
-
acting or moving or capable of acting or moving quickly; swift
-
accomplished in or lasting a short time
fast work
a fast visit
-
(prenominal) adapted to or facilitating rapid movement
the fast lane of a motorway
-
requiring rapidity of action or movement
a fast sport
-
(of a clock, etc) indicating a time in advance of the correct time
-
given to an active dissipated life
-
of or characteristic of such activity
a fast life
-
not easily moved; firmly fixed; secure
-
firmly fastened, secured, or shut
-
steadfast; constant (esp in the phrase fast friends )
-
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
-
that will not fade or change colour readily
a fast dye
-
-
proof against fading
the colour is fast to sunlight
-
( in combination )
washfast
-
-
photog
-
requiring a relatively short time of exposure to produce a given density
a fast film
-
permitting a short exposure time
a fast shutter
-
-
cricket (of a bowler) characteristically delivering the ball rapidly
-
informal glib or unreliable; deceptive
a fast talker
-
archaic sound; deep
a fast sleep
-
informal a deceptive or unscrupulous trick (esp in the phrase pull a fast one )
-
a person who achieves results quickly, esp in seductions
adverb
-
quickly; rapidly
-
soundly; deeply
fast asleep
-
firmly; tightly
-
in quick succession
-
in advance of the correct time
my watch is running fast
-
in a reckless or dissipated way
-
archaic close or hard by; very near
-
informal to behave in an insincere or unreliable manner
interjection
verb
noun
Synonym Usage
See quick.
Other Word Forms
Derived Forms
Inflected Forms
Adjectives
Participles
Conjugated Forms
Present
-
fastsimple
-
fastssimple
-
have fastedperfect
-
has fastedperfect
-
am fastingprogressive
-
are fastingprogressive
-
is fastingprogressive
-
have been fastingperfect progressive
-
has been fastingperfect progressive
Past
-
fastedsimple
-
had fastedperfect
-
was fastingprogressive
-
were fastingprogressive
-
had been fastingperfect progressive
Future
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."
Vocabulary lists containing fast
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
He instead asked how fast his presidential limousine could travel.
From Salon ● Oct. 3, 2026
“In the first half of the year we had this fast and furious rise in both earnings and earnings expectations,” said Christian Mueller-Glissmann, head of asset allocation research at Goldman Sachs.
From The Wall Street Journal ● Oct. 2, 2026
The firm also pointed out how fast startup companies can scale using AI, which will also mean they need to rely on advertising less.
From MarketWatch ● Oct. 2, 2026
Now, as I take a turn too fast, I can’t bear the thought of never seeing him again.
From Los Angeles Times ● Oct. 2, 2026
“But we’re growing so fast that I need to hire someone to help run the business side of things,” Dad says.
From "Red Flags and Butterflies" by Sheryl Azzam
“The Beast is going faster than it has ever gone before,” Trump wrote on Truth Social, referring to the heavily armored presidential limousine.
From Salon ● Oct. 3, 2026
"And because we have the results of cognitive tests these volunteers took over time, we can see that the people with the highest ImP levels also experienced much faster cognitive decline," Rey says.
From Science Daily ● Oct. 3, 2026
The bank will face a temporary drag in the second half of 2026 as liabilities reprice faster than assets, but increased deposit competition remains the main bottom-up risk.
From The Wall Street Journal ● Oct. 2, 2026
Trendforce, a research firm, said China’s manufacturing advantage could help it whittle away at America’s lead, since it could deploy humanoids faster at scale.
From MarketWatch ● Oct. 2, 2026
It’s not that I don’t want to see him, it’s just that it’ll be faster to get through the paperwork if I have the place to myself.
From "Red Flags and Butterflies" by Sheryl Azzam
It’s also the fastest way to cheapen a brand.
From The Wall Street Journal ● Oct. 3, 2026
The second Red Bull of Isack Hadjar was third fastest, 0.783secs off the pace, ahead of Ferrari's Charles Leclerc, split from his team-mate Lewis Hamilton by championship leader Kimi Antonelli's Mercedes.
From BBC ● Oct. 2, 2026
The annual rate hit 3.3 percent in Germany, Europe's biggest economy, the fastest pace since December 2023, according to preliminary data from the statistics agency Destatis.
From Barron's ● Sep. 30, 2026
If completed as scheduled, it will be the fastest trip to the International Space Station by a U.S. spacecraft in the station's history.
From Science Daily ● Sep. 30, 2026
But with the fastest runner and the champion climber of Mossflower, it was sure to be something spectacular!
From "Redwall" by Brian Jacques
Some fasts last only hours; others are carefully staged media spectacles with banners, platforms and live television coverage.
From BBC ● Jul. 16, 2026
The streets were busy with shoppers who had broken their fasts ahead of the Muslim holiday of Eid al-Adha.
From The Wall Street Journal ● May 27, 2026
Still, scientists have had only a limited understanding of exactly how the body responds during longer fasts.
From Science Daily ● May 17, 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
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
He was joined by thousands who fasted with him and held demonstrations.
From BBC ● Oct. 23, 2024
“I don’t give them all the details, but, yeah, they know. David comes over for dinner. He sometimes comes to the mosque with us. Last Ramadan, he even fasted a few days.”
From "Internment" by Samira Ahmed
By the second generation, researchers found elevated fasting blood sugar in male descendants of the sucralose group and female descendants of the stevia group.
From Science Daily ● Aug. 31, 2026
In late 2022, Elon Musk posted that he lost 30 pounds by fasting and taking semaglutide.
From MarketWatch ● Aug. 5, 2026
"Fasting, or controlled deprivation of food, is linked to a longer and healthier lifespan," says Dr Longo, who has spent three decades studying the effects of fasting.
From BBC ● Jul. 25, 2026
But not all obesity specialists are persuaded that fasting is the right approach for children.
From BBC ● Jul. 25, 2026
The radio announcer said Gandhi spent his birthday fasting and spinning yarn on his wheel.
From "The Night Diary" by Veera Hiranandani
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
