fast
gb/fˈæst/ us/fˈæst/
A1
English
~ 1800
Senses
0 senses
adjective
A1
property
1
Moving quickly
Moving very quickly.
Usage pattern:
[something] is fast
Common mistake:
Learners sometimes confuse 'fast' and 'quickly'; 'fast' is often used after 'be' verbs, while 'quickly' is an adverb modifying actions.
Synonyms
quick (Slightly more general; can refer to actions or processes, not just movement speed.)
Antonyms
slow (Describes low speed or lack of quickness.)
Collocations
fast car
|fast train
|fast runner
|fast pace
Themes
daily life
|transport
|sports
|core_vocabulary
|travel
|transportation
Examples
- The cheetah is the fastest land animal.
- She drives a very fast car.
- This computer is fast compared to my old one.
Learner examples
- The bus is fast.
- He runs fast.
- This phone is fast.
adverb
A1
property
2
At a high speed
Quickly or with high speed.
Usage pattern:
[someone] runs fast
Common mistake:
Learners may incorrectly say 'fastly'; the correct form is 'fast'.
Synonyms
quickly (More general in use; 'fast' is less formal and often used in speech.)
Antonyms
slowly (Describes doing something at a low speed.)
Collocations
run fast
|drive fast
|move fast
Themes
daily life
|sports
|core_vocabulary
Examples
- He runs surprisingly fast for his age.
- The train was moving too fast to stop in time.
- She talks fast when she’s nervous.
Learner examples
- He runs fast.
- The car moves fast.
- She speaks fast.
adjective
B1
property
3
Firmly fixed, secure
Held tightly and not able to move.
Usage pattern:
[something] is fast [somewhere]
Synonyms
secure (Emphasizes safety or protection rather than immovability.)
Antonyms
loose (Not firmly fixed or attached.)
Collocations
hold fast
|stuck fast
|fast asleep
Themes
construction
|daily life
|core_vocabulary
Examples
- The boat was held fast by the rope.
- The lid was stuck fast and wouldn’t open.
- He held her arm fast.
Learner examples
- The rope holds the boat fast.
- The lid is stuck fast.
- He holds my hand fast.
Verb
B1
action
4
Go without food for a time
To not eat for some time, often for religion or health.
Usage pattern:
to fast for [time period]
Synonyms
abstain from eating (More formal and explicit description of the action.)
Antonyms
feast (To eat a lot, often in celebration.)
Collocations
fast during Ramadan
|fast for 24 hours
Themes
religion
|health
|food_drink
Examples
- Muslims fast from dawn to sunset during Ramadan.
- Some people fast once a week for health benefits.
- He decided to fast for two days before the operation.
Learner examples
- I fast during Ramadan.
- She will fast for one day.
- They fast for health.
Noun
B1
event
5
A period of not eating food
A time when you do not eat food for religion or health.
Synonyms
abstinence from food (Formal phrase, used in medical or religious contexts.)
Antonyms
feast (An event with abundant eating.)
Collocations
religious fast
|go on a fast
Themes
religion
|health
|food_drink
Examples
- They went on a three-day fast before the ceremony.
- The doctor recommended a short fast before the test.
- Breaking the fast is an important tradition.
Learner examples
- He went on a fast.
- The fast lasts two days.
- We break the fast at night.
Grammar
Dictionary form
fast
IPA
GB/fˈæst/
US/fˈæst/
Syllables & stress
fast (1 syllable)
Stress on 1st syllable (fast)
Word forms
Adjective
- Base: fast
- Comparative: faster
- Superlative: fastest
Noun
- Base: fast
- Plural: fast, fasts
Verb
- Base: fast
- 3rd Person Singular: fasts
- Present Participle: fasting
- Past: fasted
Word family
Expressions
hold fast
1/hˈoʊld fˈæst/
fixed phrase
Keep a firm grip on something
To keep holding something tightly and not let go.
Examples
- Hold fast to the railing when climbing the stairs.
- He held fast to his beliefs despite criticism.
play fast and loose
1/plˈeɪ fˈæst ˈænd lˈus/
idiom
informal
Act carelessly or dishonestly
To behave without care or honesty, especially with rules or promises.
Examples
- The company played fast and loose with safety regulations.
- You can't play fast and loose with people's trust.
fast asleep
1/fˈæst əslˈip/
fixed phrase
sleeping very deeply
Sleeping very deeply and peacefully.
Examples
- By 10 p.m., the children were fast asleep.
- She looked so peaceful, fast asleep under the blanket.
fast asleep
2/fˈæst əslˈip/
fixed phrase
In deep sleep
Sleeping very deeply.
Examples
- She was already fast asleep when I came home.
- The baby is fast asleep in his crib.