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:
Historically, chicken was a bit of an afterthought in fast food.
From Slate ● Aug. 24, 2026
In the boldest move yet globally to curb the rise of fast fashion, France is set to impose per-item fees on Shein, Temu and other platforms deemed by the legislation to engage in "ultra-fast fashion".
From Barron's ● Aug. 24, 2026
The latest stain on the game's reputation is a result of pictures of fast bowler Brydon Carse in handcuffs and surrounded by police officers outside a nightspot in Derby.
From BBC ● Aug. 23, 2026
Thanks to the fast action of medical personnel at the game and at the hospital, he was back running track nine months later.
From Los Angeles Times ● Aug. 23, 2026
All I knew then was that we had to get to the shelter fast, as we had been taught.
From "An Elephant in the Garden" by Michael Morpurgo
SpaceX hit 100 launches in 2026 faster than it reached that mark in 2025.
From Barron's ● Aug. 24, 2026
A new analysis of biological aging across the human body suggests that both sleeping too little and sleeping too much are associated with faster aging in the brain, heart, lungs, immune system, and other organs.
From Science Daily ● Aug. 24, 2026
Next time they face a choice between another ride-share service and Zoox, the couple said they would choose Zoox, especially if it could get them to their destination faster.
From The Wall Street Journal ● Aug. 23, 2026
“This was trying to speed up that staffing faster than the departmental process normally takes in this city.”
From Los Angeles Times ● Aug. 23, 2026
The calls kept coming, unrelenting, my hands flying faster than they’d ever been asked to before.
From "The Brightwood Code" by Monica Hesse
He was so fast that in 2022, I was there at Moorpark High to see him run the fastest wind-legal 100 meters time in state history, 10.14 seconds, as he let out a primal scream.
From Los Angeles Times ● Aug. 23, 2026
Tarling now wears the white fastest young rider's jersey on stage two, which is a 214.3km hilly race to Manosque in Provence.
From BBC ● Aug. 22, 2026
“This is the fastest VW bus on the island,” he said.
From The Wall Street Journal ● Aug. 20, 2026
Astronomers have discovered the fastest star in the Milky Way zooming at 25,000 kilometres a second around the supermassive black hole at the centre of our galaxy.
From Barron's ● Aug. 20, 2026
Only he could have foreseen how two black eyes would earn her the lasting friendship of the tallest, and the strongest, and the fastest girl in all of the fifth grade.
From "In the Year of the Boar and Jackie Robinson" by Bette Bao Lord
Some fasts last only hours; others are carefully staged media spectacles with banners, platforms and live television coverage.
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 claims this dream to be divinely inspired, and fasts this day.
From "The Astonishing Life of Octavian Nothing, Traitor to the Nation, Volume II: The Kingdom on the Waves" by M.T. Anderson
Between 1918 and his assassination in 1948, Gandhi fasted repeatedly - against religious violence, caste discrimination and political discord - turning the empty plate into one of the defining symbols of India's freedom struggle.
From BBC ● Jul. 16, 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
India's activist Sonam Wangchuk has ended a hunger strike after 26 days of fasting in support of youth-led protesters demanding education reforms.
From BBC ● Jul. 23, 2026
The late fasting group used an eight hour window beginning after 1:00 p.m.
From Science Daily ● Jul. 18, 2026
It sat there tightly and grew, while he thought he was destroying it by fasting and penitence.
From "Siddhartha" by Hermann Hesse
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.
