fast
fast — adjective
- fastpositive
- fastercomparative
- fastestsuperlative
1. achieving high speed or done in little time — a fast athlete moves quickly, a fa
achieving high speed or done in little time — a fast athlete moves quickly, a fast process finishes swiftly, and a fast answer comes without delay.
Tuan took a fast train from Taipei to Kaohsiung that reached over 250 km/h.
fast + noun describing a physical object
The company saw fast growth in its first year of business.
Eli is the fastest runner on the school team and wins every race.
superlative form: fastest
Maeve needed a fast answer, so she called instead of sending an email.
Christopher made a fast recovery after breaking his arm in the fall.
collocation: fast recovery
- fast car
- fast train
- fast growth
- fast answer
- fast recovery
- fast learner
- fast pace
- quick
very similar in meaning; 'quick' often emphasises short duration ('quick shower') while 'fast' emphasises high speed ('fast car')
- rapid
more formal than 'fast'; commonly used with processes and changes ('rapid population growth')
- swift
slightly more literary; suggests smooth, effortless speed ('swift response')
- speedy
informal; focuses on completion without delay ('speedy delivery')
- slow
the direct opposite for speed and duration
Grammar Patterns
fast + noun (car, train, growth)
be + fast
Usage Note
This is the most common sense of 'fast' and applies to physical speed (vehicles, people), rate of change (growth, progress), and short duration (response, recovery).
Common Mistakes
❌ 'He is a fast learner' (acceptably correct) — note that 'fast' here describes the person's ability, not their physical speed.
2. used when a timepiece gives a reading that is ahead of the actual moment — for i
used when a timepiece gives a reading that is ahead of the actual moment — for instance, a clock showing 8:03 when the real time is 8:00 is said to be three minutes fast.
Sade's watch is five minutes fast, so she always arrives early for class.
number + minutes/hours + fast
Erik noticed the classroom clock was fast and told the teacher about it.
If your phone clock is fast, you might show up before the movie starts.
The timer on the oven runs fast, so Camila set it ten minutes behind.
runs fast — verb + fast for timekeeping devices
- five minutes fast
- ten minutes fast
- runs fast
- is fast
- ahead
less common for clocks; 'the clock is ahead' means the same but is much rarer
- slow
showing a time earlier than the correct time
Grammar Patterns
clock / watch + be + fast
run + amount + fast
Usage Note
Only used for timekeeping devices (clocks, watches, timers). Not used for calendars or schedules. The opposite is 'slow'.
Common Mistakes
3. describing photographic film or camera equipment that responds well in dim condi
describing photographic film or camera equipment that responds well in dim conditions, allowing you to capture sharp images even with little illumination or of subjects that are moving.
Hiro bought fast film for taking pictures at the indoor concert.
fast + film
A fast lens helps you take clear photos in low light without a flash.
fast + lens
Sports photographers use fast shutter speeds to capture moving athletes.
fast + shutter speed
The camera's fast sensor captured each feather on the flying bird.
- fast film
- fast lens
- fast shutter speed
- fast sensor
- high-speed
slightly broader; 'high-speed film' and 'fast film' are interchangeable
- sensitive
describes the light sensitivity directly but is less specific to photography than 'fast'
- slow
slow film or slow lens requires more light
Grammar Patterns
fast + noun (film, lens, shutter)
Usage Note
Mainly used in photography contexts. A 'fast' lens has a wide aperture (small f-number) that lets in more light. 'Fast' film has a high ISO number.
4. full of quick action, excitement, and rapid changes; describing an experience, p
full of quick action, excitement, and rapid changes; describing an experience, place, or activity that feels energetic and never slows down.
Sumin enjoys fast action movies with car chases and fight scenes.
fast + action movie / pace
Life in a big city is fast and can feel stressful at first.
be + fast describing lifestyle
The video game's fast pace kept the players focused for many hours.
Élise loves the fast atmosphere of the newsroom where she works.
- fast pace
- fast action
- fast life
- fast atmosphere
- fast city
- lively
positive and less intense; suggests enjoyable energy rather than pressure ('lively discussion')
- hectic
more negative; suggests stressful, chaotic busyness ('hectic schedule')
- high-energy
informal; emphasises excitement and intensity
- slow-paced
describes something that moves at a relaxed or leisurely rate
- relaxed
the opposite of a fast, stressful environment
Grammar Patterns
fast + noun (pace, life, city)
be + fast
Usage Note
Describes experiences, lifestyles, and entertainment — not physical speed of an object. A 'fast movie' means it has lots of action, not that it plays at high speed.
5. living in a way that others consider morally careless, especially by seeking too
living in a way that others consider morally careless, especially by seeking too much pleasure or by being sexually unrestrained — this meaning is dated and often sounds disapproving.
The novel tells the story of a fast social crowd in 1920s New York.
Evelyn's grandmother warned her about spending time with a fast crowd downtown.
fast + crowd / set / life
In old films, a fast woman was a character who broke social rules.
The newspaper described the party as fast and full of wild behaviour.
informal register: fast party
- fast crowd
- fast woman
- fast life
- fast set
- fast living
- wild
broader and less judgmental; can describe energetic fun without moral criticism ('wild party')
- promiscuous
specifically about sexual behaviour; more clinical and neutral in tone
- dissolute
formal and literary; describes someone who lives without moral restraint
Grammar Patterns
fast + noun (crowd, woman, life)
Usage Note
This sense is dated and carries a strong disapproving tone. Avoid using it to describe people directly in modern conversation — it can sound rude or judgmental. Limited mostly to historical or literary contexts.
Common Mistakes
6. used for a dye or pigment that stays in the fabric it was applied to, so it does
used for a dye or pigment that stays in the fabric it was applied to, so it does not run, fade, or wash away when the item is cleaned or left in the sun.
Camila checked the label to see if the red dress was colour-fast.
compound: colour-fast
The dye on these jeans is fast, so you can wash them with other clothes.
Cyrus bought a rug with colours that stay fast even in bright sunlight.
stay fast — verb + fast for colour retention
Always wash new dark clothes in cold water until the colour is fast.
- colour-fast
- stay fast
- colour is fast
- wash-fast
- colour-safe
a commercial term; 'colour-safe bleach' won't damage fast colours but the term isn't used for the fabric itself
- fade-resistant
more modern and specific; commonly used for outdoor fabrics ('fade-resistant paint')
- fading
losing colour over time
Grammar Patterns
colour / dye + be + fast
Usage Note
Often used in the hyphenated compound 'colour-fast' (or 'color-fast' in American English). Common on clothing labels and washing instructions. The opposite is 'the colour runs'.
7. securely attached or held in position; not easily moved, loosened, or changed —
securely attached or held in position; not easily moved, loosened, or changed — often used for physical objects that are stuck or tied firmly.
The cupboard door was fast and would not open no matter how hard Liam pushed.
be + fast describing a stuck object
The painter made sure the ladder was fast before climbing to the roof.
During the storm, all the windows were checked to make sure they were fast.
Padma tied a double knot to keep the rope fast around the tree trunk.
keep + object + fast — verb + object + complement
- make fast
- hold fast
- stick fast
- stay fast
- keep fast
- secure
broader; can describe safety from danger as well as firm attachment ('secure knot')
- firm
general-purpose; used for both physical and figurative stability ('firm grip')
- tight
suggests physical pressure keeping something in place ('tight lid')
- stuck
informal; emphasises that something cannot be moved ('stuck window')
Grammar Patterns
be + fast
hold + object + fast
stick + fast
Usage Note
Frequently paired with verbs such as 'hold', 'stick', 'stay', 'keep', and 'make'. In the phrase 'hold fast', 'fast' can be read as an adverb describing how the holding is done — the boundary between adjective and adverb is blurry in this sense.
Common Mistakes
To understand or react very quickly in a new situation.
Maya is fast on the draw when it comes to solving puzzles.
In debates, Diego is quick on the draw with sharp replies.
To understand or react very quickly in a new situation.
Sara is quick on the draw during emergency drills.
Is Brian always fast on the draw with new ideas?
fast and furious
idiomFull of rapid action and sudden changes.
The car chase in the film was fast and furious.
Trading on the stock market became fast and furious.
a fast talker
idiomA person who speaks very quickly and easily but may not be trustworthy.
The salesman was a fast talker who sold us a broken car.
Don't trust that fast talker; he always exaggerates.
a fast worker
idiomA person who knows how to get what they want quickly, especially in romantic situations.
Tom is a fast worker; he asked her out on the first day.
Mia is a fast worker when it comes to negotiating deals.
hard and fast
idiomFixed and impossible to change under any circumstances.
There are no hard and fast rules for writing a novel.
Is this deadline hard and fast, or can we extend it?
To earn money quickly and easily, often without much effort.
He tried to make a quick buck by selling fake watches.
She is not interested in making a fast buck; she wants a career.
To trick or deceive someone.
The mechanic pulled a fast one on me by charging for extra repairs.
Did the con artist pull a fast one on the old lady?
fast — adverb
1. at great speed; in a way that takes very little time — for example, running fast
at great speed; in a way that takes very little time — for example, running fast, driving fast, or learning fast.
The children ran as fast as they could to catch the school bus.
as fast as + clause
Evelyn learns fast and finished the training course in just two weeks.
verb + fast (learn, work, think)
Please drive as fast as you safely can — we are already late.
Karim's heart was beating fast after the run up the steep hill.
- run fast
- drive fast
- learn fast
- work fast
- think fast
- beat fast
- grow fast
- slowly
at a low speed; taking a long time
Grammar Patterns
verb + fast
as fast as
Usage Note
The adverb form of 'fast' is identical to the adjective — there is no word 'fastly'. Use 'fast' after action verbs (run, drive, work, learn, grow).
Common Mistakes
2. in a firmly fixed or securely attached way; with strong determination not to mov
in a firmly fixed or securely attached way; with strong determination not to move or change position.
The soldiers stood fast against the enemy attack all through the night.
stand fast — fixed phrase for physical or moral resistance
Hiro held fast to his dream of becoming a doctor despite the challenges.
hold fast to — figurative: keep believing in
The boat was stuck fast in the mud when the tide went out.
Ife held fast to the railing as the train moved through the tunnel.
- hold fast
- stand fast
- stick fast
- hold fast to
- loosely
not firmly; with slack or give
Grammar Patterns
hold + fast
stand + fast
stick + fast
Usage Note
This adverb sense appears in three main fixed phrases: 'hold fast' (physical grip or figurative commitment), 'stand fast' (refuse to change position or opinion), and 'stick fast' (physically unable to move). Unlike the 'quickly' adverb sense, this one cannot be used freely with other verbs.
Common Mistakes
fast — noun
- fastsingular
- fastsplural
1. a stretch during which someone deliberately eats very little or nothing at all,
a stretch during which someone deliberately eats very little or nothing at all, often for religious, spiritual, health-related, or medical reasons.
During Ramadan, Muslims observe a daily fast from sunrise to sunset.
observe a fast — formal/religious use
Yasmin went on a three-day fast to help clean out her body.
go on a fast — start a fasting period
Some people break their fast with a light meal of soup and bread.
break one's fast — eat after a fasting period
The doctor warned that a long fast can be dangerous without drinking water.
- observe a fast
- break a fast
- go on a fast
- keep a fast
- daily fast
- long fast
Grammar Patterns
a + (number) + fast
break + one's + fast
go on + a + fast
Usage Note
Often used with the verbs 'observe', 'keep', 'break', and 'go on'. The word 'breakfast' literally means 'breaking the fast' after a night of sleep.
Common Mistakes
fast — verb
- fastpresent simple I / you / we / they
- fasts3rd person singular
- fasting-ing form
- fastedpast simple
1. to go without eating on purpose over a set stretch, typically for religious obse
to go without eating on purpose over a set stretch, typically for religious observance, health reasons, or medical preparation.
Cyrus fasts for sixteen hours every day as part of his diet plan.
fast + for + duration
Many Christians fast during the season of Lent before Easter Sunday.
fast during + period (religious observance)
The patient had to fast for twelve hours before the blood test.
Mira felt dizzy after fasting for the whole day without drinking any water.
fasting — gerund form as subject/object
- fast for
- fast during
- fast from
- fast before
- feast
to eat a large, elaborate meal, often in celebration
Grammar Patterns
fast + for + period of time
fast + from + time + to + time
Usage Note
This verb is intransitive — you do not fast 'something'. You fast for a period of time or from a specific time. To describe what you avoid, use 'fast from + food/drink' (e.g., 'fast from meat').
Common Mistakes
Word family
Synonym discussion
Sense: adjective/1
Fast is the most general and common word for high speed. It works for physical movement (fast car), mental ability (fast learner), and duration (fast response). Quick often emphasises short duration or mental agility (quick decision, quick shower) and is very common in everyday speech. Rapid is more formal and appears frequently in writing about change or development (rapid growth, rapid improvement). Swift has a smoother, more graceful quality and is often found in formal or literary contexts (swift response, swift justice). Speedy is informal and focuses on completing something without delay (speedy delivery, speedy recovery). For everyday use, 'fast' is the safest choice — it fits most situations naturally. If you want to sound more formal, choose 'rapid' for processes or 'swift' for decisions and reactions.
Common collocations
Etymology
The modern word 'fast' comes from two different Old English roots that have blended together over time. The meaning 'quick, speedy' comes from Old English 'fæst' meaning 'firm, fixed' — the same word that gave us the 'firmly fixed' sense. The shift from 'firm' to 'quick' happened because in Old English, running 'firmly' or 'steadfastly' came to imply running 'strongly' or 'vigorously', which then became 'quickly'. The 'abstain from food' meaning comes from a different Old English verb 'fæstan' (to fast, to abstain), which is related to similar words in other Germanic languages such as German 'fasten' and Dutch 'vasten'.
First known use
12th century
12th century, in the meaning defined at sense 2 Adverb