fast
1 of 5adjective
ˈfast 
1
a
: firmly fixed
roots fast in the ground
b
: tightly shut
the drawers were fast
c
: adhering firmly
The boards were fast a few hours after being glued together.
d
: not easily freed : stuck
a ball fast in the mouth of the cannon
e
: stable
movable items were made fast to the deck
2
: firmly loyal
became fast friends
3
a
: characterized by quick motion, operation, or effect:
(1)
: moving or able to move rapidly : swift
a fast horse
(2)
: taking a comparatively short time
a fast race
(3)
: imparting quickness of motion
a fast bowler
(4)
: accomplished quickly
fast work
(5)
: agile of mind
especially : quick to learn
a class for fast students
b
: conducive to rapidity of play or action
a fast track
c(1)
of a timepiece or weighing device : indicating in advance of what is correct
Your clock is two minutes fast.
(2)
: according to or being daylight saving time
d
: contributing to a shortening of exposure time
fast film
e
: acquired with unusually little effort and often by shady or dishonest methods
had a keen eye for a fast buck—
R. A. Keith
R. A. Keith4
a
: securely attached
a rope fast to the wharf
b
: tenacious
a fast hold on her purse
5
a
archaic : sound asleep
b
of sleep : not easily disturbed
fell into a fast sleep
6
: not fading or changing color readily
fast colors
7
a
: actively seeking excitement and pleasure : wild
a pretty fast crowd
b
: sexually promiscuous
8
: resistant to change (as from destructive action or fading)
fast dyes
—often used in combination sunfastacid-fast bacteria
fast
2 of 5adverb
1
: in a firm or fixed manner
stuck fast
2
: in a sound manner : deeply
fast asleep
3
a
: in a rapid manner : quickly
b
: in quick succession
4
: in a reckless or dissipated manner
5
: ahead of a correct time or schedule
6
archaic : close, near
fast
3 of 5verb
fasted; fasting; fasts
intransitive verb
1
: to abstain from food
2
: to eat sparingly or abstain from some foods
fast
4 of 5noun (1)
1
: the practice of fasting
2
: a time of fasting
fast
5 of 5noun (2)
: something that fastens (such as a mooring line) or holds a fastening
Synonyms
Adjective
- blistering
- breakneck
- breathless
- brisk
- dizzy
- fleet
- fleet-footed
- flying
- galloping
- hasty
- hot
- lightning
- nippy
- quick
- rapid
- rapid-fire
- rattling
- snappy
- speedy
- splitting
- swift
- whirlwind
- zippy
Adverb
- apace
- briskly
- chop-chop
- double-quick
- fleetly
- full tilt
- hastily
- hell-for-leather
- hot
- lickety-split
- posthaste
- presto
- pronto
- quick
- quickly
- rapidly
- snappily
- soon
- speedily
- swift
- swiftly
See all Synonyms & Antonyms 
Example Sentences
Adjective She's a very fast runner. We're off to a fast start. We're now experiencing a faster rate of inflation. We took the faster route. Adverb The boss expects this to be done this afternoon, so you'd better work fast. He ran as fast as he could. This is fast becoming a national problem. You need to act fast to take advantage of this offer. I don't know what caused the accident. It all happened so fast. She's a woman who can think fast in a crisis. He's going to have to talk fast to get himself out of this mess. The window was stuck fast. She held fast to her belief in justice. We must stand fast and not surrender! Verb She always fasts on Yom Kippur. Patients must fast for six hours before having the procedure. See More
Recent Examples on the WebJulia Landwehr, Health, 10 Feb. 2023 Because of the need to fast, the test is usually done in the morning. —Verywell Health, 30 Jan. 2023 For starters, Mardi Gras festivities are in full swing in the Big Easy and other places around the globe the last Tuesday before Lent — the six-week period from Ash Wednesday leading up to Easter during which Christians fast, repent and pray. —Karla Pope, Good Housekeeping, 24 Jan. 2023 While your iPhone may be capped to a charge speed of 18 watts, your MacBook Pro might fast charge at 67 watts. —Hunter Fenollol, Popular Mechanics, 20 Dec. 2022 The primary intent of the Exipure weight loss pills is to fast forward your weight loss journey by maximizing the production of brown fat cells inside your body. —James Robinson, Discover Magazine, 14 Dec. 2022 First meeting between programs features running backs off to fast starts this season. —J.c. Carnahan, Orlando Sentinel, 8 Sep. 2022 Go ahead and fix yourself a fall cocktail while checking out our best fall season quotes to fast forward to autumn. —Adam Schubak, Country Living, 18 Aug. 2022 In 2019, Menna Shahin had an idea particularly inspired by Ramadan, the Muslim holiday when the devout give to poor people and fast throughout the day. —Eman Mounir, The Christian Science Monitor, 4 Aug. 2022 Amber Smith, Discover Magazine, 30 Jan. 2023 There’s nothing much worse than spending an evening with a group of people who are about to start a diet, a punitive exercise regime, a detox or a fast. —Time, 30 Dec. 2022 Starting such a blurry fast, physically demanding sport at 55 might not have been the wisest move. —Houston Mitchell, Los Angeles Times, 6 Dec. 2022 Owens was two weeks into the fast on November 14 when Cook and Meadows, now 50 and 48 years old, stood before her again. —Roy S. Johnson | Rjohnson@al.com, al, 5 Dec. 2022 By Wednesday, the fifth day of his fast, John was weakening. —John Rosengren, Washington Post, 30 Nov. 2022 An iftar is defined by Merriam-Webster as a meal eaten by Muslims at sundown to break the daily fast of Ramadan. —Hannah Hudnall, USA TODAY, 30 Nov. 2022 Lib also learns the reason Anna was convinced to go along with the religious fast. —Town & Country, 18 Nov. 2022 With dwindling sea ice, there is less opportunity for polar bears to fatten up in preparation for the annual fast, leaving them food-deprived for longer periods of time. —Julia Jacobo, ABC News, 10 Nov. 2022 See More
Verb
It’s recommended that people fast for eight to 12 hours before the screening, but beyond that, there’s very little prep needed for the CVS heart health screening. —Julia Landwehr, Health, 10 Feb. 2023 Because of the need to fast, the test is usually done in the morning. —Verywell Health, 30 Jan. 2023 For starters, Mardi Gras festivities are in full swing in the Big Easy and other places around the globe the last Tuesday before Lent — the six-week period from Ash Wednesday leading up to Easter during which Christians fast, repent and pray. —Karla Pope, Good Housekeeping, 24 Jan. 2023 While your iPhone may be capped to a charge speed of 18 watts, your MacBook Pro might fast charge at 67 watts. —Hunter Fenollol, Popular Mechanics, 20 Dec. 2022 The primary intent of the Exipure weight loss pills is to fast forward your weight loss journey by maximizing the production of brown fat cells inside your body. —James Robinson, Discover Magazine, 14 Dec. 2022 First meeting between programs features running backs off to fast starts this season. —J.c. Carnahan, Orlando Sentinel, 8 Sep. 2022 Go ahead and fix yourself a fall cocktail while checking out our best fall season quotes to fast forward to autumn. —Adam Schubak, Country Living, 18 Aug. 2022 In 2019, Menna Shahin had an idea particularly inspired by Ramadan, the Muslim holiday when the devout give to poor people and fast throughout the day. —Eman Mounir, The Christian Science Monitor, 4 Aug. 2022 Noun
Will a tablespoon of cream in my coffee break my fast? —Amber Smith, Discover Magazine, 30 Jan. 2023 There’s nothing much worse than spending an evening with a group of people who are about to start a diet, a punitive exercise regime, a detox or a fast. —Time, 30 Dec. 2022 Starting such a blurry fast, physically demanding sport at 55 might not have been the wisest move. —Houston Mitchell, Los Angeles Times, 6 Dec. 2022 Owens was two weeks into the fast on November 14 when Cook and Meadows, now 50 and 48 years old, stood before her again. —Roy S. Johnson | Rjohnson@al.com, al, 5 Dec. 2022 By Wednesday, the fifth day of his fast, John was weakening. —John Rosengren, Washington Post, 30 Nov. 2022 An iftar is defined by Merriam-Webster as a meal eaten by Muslims at sundown to break the daily fast of Ramadan. —Hannah Hudnall, USA TODAY, 30 Nov. 2022 Lib also learns the reason Anna was convinced to go along with the religious fast. —Town & Country, 18 Nov. 2022 With dwindling sea ice, there is less opportunity for polar bears to fatten up in preparation for the annual fast, leaving them food-deprived for longer periods of time. —Julia Jacobo, ABC News, 10 Nov. 2022 See More Word History
Etymology
Adjective and Adverb
Middle English, from Old English fæst; akin to Old High German festi firm, Old Norse fastr, Armenian hast
Verb and Noun (1)
Middle English, from Old English fæstan
Noun (2)
alteration of Middle English fest, from Old Norse festr rope, mooring cable, from fastr firm
First Known Use
Adjective
before the 12th century, in the meaning defined at sense 1a
Adverb
before the 12th century, in the meaning defined at sense 1
Verb
before the 12th century, in the meaning defined at sense 1
Noun (1)
12th century, in the meaning defined at sense 1
Noun (2)
15th century, in the meaning defined above
Phrases Containing fast
Kids Definition
fast
1 of 4 adjective ˈfast
1
a
: firmly fixed or bound
b
: tightly shut
c
: sticking firmly
2
: firmly loyal
became fast friends
3
a
: moving or able to move rapidly
b
: taking a short time
c
: giving quickness of motion (as to a thrown ball)
d
: favorable to speed
the faster route
4
: indicating ahead of the correct time
my clock is fast
5
: tricky and unfair
pulled a fast one
6
: not likely to fade
fast colors
fast
2 of 4 adverb1
: in a fixed manner
stuck fast
2
: in a complete manner : soundly, deeply
fast asleep
3
: with great speed
a building fast going to ruin
fast
3 of 4 verb1
: to go without eating
2
: to eat in small amounts or only certain foods
fast
4 of 4 noun1
: the act of fasting
2
: a time of fasting
Medical Definition
fast
1 of 3 adjective ˈfast
1
: firmly fixed
2
a
: having a rapid effect
a fast medicine
b
: allowing for the rapid passage of a gas or liquid
3
: resistant to change (as from destructive action) —used chiefly of organisms and in combination with the agent resisted
acid-fast bacteria
fast
2 of 3 intransitive verb1
: to abstain from food
2
: to eat sparingly or abstain from some foods
transitive verb
: to deny food to
the patient is fasted and given a mild hypnotic—Lancet
Lancetfast
3 of 3 noun1
: the practice of fasting
2
: a time of fasting
fast 1 of 4
adverb
1
as in quickly
with great speed run as fast as you can to get help Synonyms & Similar Words
Relevance
- quickly
- quick
- rapidly
- swiftly
- hot
- soon
- swift
- immediately
- promptly
- speedily
- hastily
- briskly
- at full tilt
- apace
- like gangbusters
- fleetly
- at full throttle
- like wildfire
- presto
- lickety-split
- double-quick
- full tilt
- in short order
- abruptly
- by leaps and bounds
- posthaste
- in a hurry
- chop-chop
- pronto
- like a shot
- hell-for-leather
- snappily
- readily
- a mile a minute
- recklessly
- vigorously
- impulsively
- suddenly
- rashly
- impetuously
- energetically
Antonyms & Near Antonyms
- slowly
- slow
- sluggishly
- leisurely
- deliberately
- ploddingly
- laggardly
- belatedly
- tardily
- lingeringly
- delinquently
2
as in quite
to a full extent or degree everyone in camp was fast asleep within minutes of hitting the sack Synonyms & Similar Words
- quite
- perfectly
- all
- completely
- wide
- well
- fully
- totally
- utterly
- even
- thoroughly
- out
- wholly
- exactly
- enough
- entire
- absolutely
- entirely
- clean
- flat
- full
- dead
- for fair
- all of
- all the way
- all over
- in whole
- basically
- at length
- cold
- soundly
- to pieces
- down to the ground
- heartily
- altogether
- plain
- mostly
- down the line
- generally
- substantially
- downright
- to the hilt
- plumb
- to the max
- to bits
- largely
- through and through
- mainly
- greatly
- predominantly
- primarily
- stone
- overall
- stone-cold
- unqualifiedly
- principally
- categorically
- predominately
- abundantly
- chiefly
- hands down
- generously
- by and large
- copiously
- more or less
Antonyms & Near Antonyms
- halfway
- just
- partly
- slightly
- partially
- hardly
- half
- barely
- minimally
- somewhat
- marginally
- scarcely
- superficially
- incompletely
- part
- roughly
- approximately
- kind of
fast
2 of 4adjective
1
as in rapid
moving, proceeding, or acting with great speed the fast pace of construction resulted in our new house being done ahead of schedule Synonyms & Similar Words
- rapid
- quick
- galloping
- brisk
- swift
- speedy
- breakneck
- hot
- lightning
- hasty
- flying
- whirlwind
- hurried
- accelerated
- rattling
- zippy
- breathless
- snappy
- splitting
- fleet
- blistering
- rapid-fire
- dizzy
- expeditious
- at speed
- fleet-footed
- nippy
- strong
- rushed
- ready
- vigorous
- prompt
- rush
- quickened
- breathtaking
- energetic
- hastened
- strenuous
- ultrafast
- high-speed
- ultrarapid
Antonyms & Near Antonyms
- slow
- sluggish
- unhurried
- crawling
- dragging
- languid
- leisurely
- pokey
- deliberate
- plodding
- poky
- laggard
- lingering
- slowish
- late
- dallying
- measured
- dilatory
- tardy
- dawdling
- dillydallying
- poking
- ultraslow
2
as in steadfast
firm in one's allegiance to someone or something the two girls soon became fast and inseparable friends Synonyms & Similar Words
- steadfast
- loyal
- good
- faithful
- staunch
- true
- steady
- devout
- dedicated
- devoted
- constant
- reliable
- pious
- dependable
- stanch
- solid
- ardent
- fervent
- trustworthy
- down-the-line
- passionate
- responsible
- enthusiastic
- true-blue
- dutiful
- tried
- unhesitating
- trusty
- resolute
- unwavering
- determined
- serious
- intent
- unfaltering
- tried-and-true
- fervid
- sworn
- impassioned
- avid
- confirmed
- inveterate
- gung ho
- dyed-in-the-wool
Antonyms & Near Antonyms
- unreliable
- treacherous
- fickle
- untrue
- false
- inconstant
- disloyal
- unfaithful
- irresponsible
- faithless
- perfidious
- undependable
- traitorous
- untrustworthy
- hesitant
- uncertain
- shaky
- faltering
- dubious
- irresolute
- recreant
- dispassionate
- uninterested
- apathetic
- wavering
- vacillating
3
as in stuck
firmly positioned in place and difficult to dislodge the rusty, old screws are so fast in the fitting that there's no hope of getting them out Synonyms & Similar Words
- stuck
- tight
- jammed
- frozen
- glued
- lodged
- set
- wedged
- snug
- embedded
- firm
- fastened
- secured
- attached
- anchored
- bonded
- clamped
- bound
- cemented
- impacted
- entrenched
- immovable
- imbedded
- intrenched
- unyielding
- implanted
Antonyms & Near Antonyms
- loose
- insecure
- unsecured
- detached
- unbound
- movable
- unattached
- undone
- freed
- moveable
- yielding
- loosened
- unfastened
- dislodged
4
as in deceptive
given to or marked by cheating and deception rolling back odometers was just one of the fast practices that the used-car dealer was guilty of Synonyms & Similar Words
- deceptive
- fraudulent
- shady
- crooked
- dishonest
- sharp
- shifty
- false
- rogue
- bent
- underhand
- guileful
- underhanded
- duplicitous
- artful
- treacherous
- slick
- unscrupulous
- cunning
- subtle
- unethical
- deceiving
- slippery
- unprincipled
- deceitful
- tricky
- unconscionable
- wily
- sly
- double-dealing
- crafty
- sneaky
- beguiling
- cagey
- foxy
- insidious
- delusive
- furtive
- trickish
- delusory
- devious
- perfidious
- cagy
- deluding
- sneaking
- defrauding
Antonyms & Near Antonyms
- straight
- honest
- decent
- honorable
- ethical
- conscientious
- just
- straightforward
- scrupulous
- upright
- aboveboard
- forthright
5
as in sturdy
marked by the ability to withstand stress without structural damage or distortion as the storm approached, we checked to see that every thing on the outside of the house was fast and locked in position Synonyms & Similar Words
- sturdy
- strong
- stable
- reliable
- durable
- sound
- dependable
- firm
- bombproof
- stalwart
- solid
- tough
- unbreakable
- beefy
- cohesive
- infrangible
- irrefragable
Antonyms & Near Antonyms
- unstable
- weak
- unsteady
- rickety
- unsound
- shaky
- insecure
- unbalanced
- wobbly
- infirm
- wabbly
- unsubstantial
- tottery
- tottering
6
as in short
not lasting for a considerable time after a fast explanation of the procedure, we were turned loose to do the work Synonyms & Similar Words
- short
- brief
- little
- sudden
- concise
- compact
- shortened
- transient
- condensed
- abrupt
- succinct
- shortish
- syncopated
- ephemeral
- abbreviated
- curtailed
- fleeting
- transitory
- crisp
- laconic
- pithy
- terse
- abridged
- momentary
- cut-back
- summary
- epigrammatic
- impermanent
- short-lived
- compendious
- short-term
- short-range
Antonyms & Near Antonyms
- long
- great
- far
- lengthy
- persistent
- extended
- endless
- everlasting
- prolonged
- unending
- interminable
- permanent
- protracted
- longish
- long-lived
- overlong
- long-drawn-out
- long-drawn
- enlarged
- expanded
- supplemented
- long-term
- long-range
7
as in quick
having or showing quickness of mind I don't know how to operate this machine, but I'm a fast learner Synonyms & Similar Words
- quick
- intelligent
- smart
- clever
- brilliant
- sharp
- exceptional
- bright
- nimble
- keen
- wise
- skilled
- wise
- educated
- brainy
- alert
- quick-witted
- ultrasmart
- supersmart
- cunning
- sensible
- resourceful
- sharp-witted
- schooled
- learned
- acute
- creative
- literate
- apt
- ingenious
- reasonable
- savvy
- insightful
- hyperintelligent
- perceptive
- astute
- prudent
- sound
- trained
- knowledgeable
- logical
- heady
- informed
- knowing
- cerebral
- sane
- sagacious
- judicious
- scholarly
- inventive
- rational
- discerning
- erudite
- perspicacious
- highbrow
- genial
- shrewd
- wily
- percipient
- sage
- crafty
- foxy
- sapient
- well-read
- sapient
Antonyms & Near Antonyms
- slow
- simple
- thick
- dense
- stupid
- dumb
- soft
- dull
- opaque
- dim
- mindless
- unintelligent
- obtuse
- vacuous
- fatuous
- dopey
- brainless
- witless
- unbrilliant
- senseless
- thickheaded
- doltish
- unsmart
- boneheaded
- lamebrain
- dopy
- lamebrained
- dorky
- pinheaded
- softheaded
- dunderheaded
- silly
- foolish
- knuckleheaded
- simpleminded
- feebleminded
- idiotic
- bubbleheaded
- gormless
- chuckleheaded
- moronic
- imbecile
- idiotical
- ignorant
- airheaded
- imbecilic
- lunkheaded
- brain-dead
- dim-witted
- unthinking
- slow-witted
- uneducated
- illiterate
- thick-witted
- birdbrained
- insane
- crazy
- mad
- uninformed
- weak-minded
- empty-headed
- absurd
- unwise
- unintellectual
- untaught
- lowbrow
- half-witted
- unacademic
- nonintellectual
- nutty
- zany
- nonsensical
- preposterous
- wacky
- fool
- cuckoo
- sappy
- asinine
- boobish
- whacky
- daft
- lunatic
- balmy
- loony
- dippy
- kooky
- daffy
- dotty
- screwball
- harebrained
- half-baked
- looney
- cockeyed
- crackpot
- featherheaded
- tomfool
- kookie
- half-baked
fast
3 of 4noun
as in famine
Synonyms & Similar Words
- famine
- craving
- starvation
- sweet tooth
- hoggishness
- gluttony
- hunger strike
- greed
- gourmandism
- undernourishment
- voracity
- malnutrition
- stomach
- rapacity
- famishment
- hunger
- voraciousness
- ravenousness
- belly
- appetite
- rapaciousness
- emptiness
- munchies
Antonyms & Near Antonyms
- satisfaction
- fill
- fullness
- satiety
- glut
- satiation
- surfeit
- inappetence
- repletion
- repleteness
fast
4 of 4verb
as in to diet
Synonyms & Similar Words
- diet
Antonyms & Near Antonyms
- stuff
- sate
- gobble
- gorge
- cram
- glut
- surfeit
- pig out
- gulp
- gormandize
- guzzle
Synonym Chooser
Some common synonyms of fast are expeditious, fleet, hasty, quick, rapid, speedy, and swift. While all these words mean "moving, proceeding, or acting with celerity," fast and rapid are very close in meaning, but fast applies particularly to the thing that moves.
fast horses
The words expeditious and fast are synonyms, but do differ in nuance. Specifically, expeditious suggests efficiency together with rapidity of accomplishment.
the expeditious handling of an order
While the synonyms fleet and fast are close in meaning, fleet adds the implication of lightness and nimbleness.
fleet runners
Although the words hasty and fast have much in common, hasty suggests hurry and precipitousness and often connotes carelessness.
a hasty inspection
In some situations, the words quick and fast are roughly equivalent. However, quick suggests promptness and the taking of little time.
a quick wit
The meanings of rapid and fast largely overlap; however, rapid applies to the movement itself, rather than to the thing that moves.
rapid current
The words speedy and fast can be used in similar contexts, but speedy implies quickness of successful accomplishment and may also suggest unusual velocity.
speedy delivery of mail
While in some cases nearly identical to fast, swift suggests great rapidity coupled with ease of movement.
returned the ball with one swift stroke
- garrapata
- garred
- garret
- garreteer
- garreteers
- garrets
- Garrick
- garrigue
- garring
- garrison
- garrison backstay
- garrison cap
- garrison caps
- garrison court-martial
- Garrison Dam
- Garrison finish
- garrison flag
- garrison house
- garrison houses
- garrison prisoner
- garrison ration
- garrison state
- garrisoned
- Garrisonian
- garrisoning