fast
/fæst/adjective, noun, interjection, adverb, verb
fast is spelled F-A-S-T: 4 letters and one syllable. It appears 135 times per million words in written English, the 770th most frequent word form (wordfreq, 2021 data). As an adjective, fast means “Firmly or securely fixed in place; stable” (English Wiktionary, September 2026).
How many letters and syllables are in fast?
| Letters | 4: F-A-S-T |
|---|---|
| Syllables | 1 (from its American pronunciation) |
| In writing | 135 times per million words; the 770th most frequent word form |
| Wrong spellings searched | none measured in search |
| Rhymes with |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is fast?
Fast appears 135 times per million words in written English, the 770th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce fast?
- UK /fɑːst/
- US /fæst/
Fast has one syllable (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-uk-fast.ogg, En-us-fast.ogg, Wikimedia Commons (author and licence on each file's page).
What rhymes with fast?
The 12 most written words on PlainSpell end in the same sounds as fast from its last stressed vowel (/æst/):
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of fast
- faster comparative
- fastest superlative
- fasts plural, present, singular, he/she/it
- fasting participle, present
- fasted participle, past
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does fast mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
datedFirmly or securely fixed in place; stable.
That rope is dangerously loose. Make it fast!
- 2
Firm against attack; fortified by nature or art; impregnable; strong.
- 3
Steadfast, with unwavering feeling. (Now mostly in set phrases like fast friend(s).)
- 4
Moving with great speed, or capable of doing so; swift, rapid; light.
I am going to buy a fast car.
- 5
Having a kinetic energy between 1 million and 20 million electron volts; often used to describe the energy state of free neutrons at the moment of their release by a nuclear fission or nuclear fusion reaction (i.e., before the neutrons have been slowed down by anything).
Plutonium-240 has a much higher fission cross-section for fast neutrons than for thermal neutrons.
- 6
Of a place, characterised by business, hustle and bustle, etc.
- 7
Causing unusual rapidity of play or action.
a fast racket, or tennis court
- 8
Able to transfer data in a short period of time.
noun
- 1
UKA train that calls at only some stations it passes between its origin and destination, typically just the principal stations.
- 2
The act or practice of fasting, religious abstinence from food.
- 3
Any of the fasting periods in the liturgical year.
adverb
- 1
In a firm or secure manner, securely; in such a way as not to be moved; safe, sound .
Hold this rope as fast as you can.
- 2
Deeply or soundly .
The princess was sleeping fast, and her servants were fast asleep too.
- 3
Immediately following in place or time; close, very near .
The horsemen came fast on our heels.
- 4
Quickly, with great speed; within a short time .
Do it as fast as you can.
- 5
Ahead of the correct time or schedule.
I think my watch is running fast.
verb
- 1
To practice religious abstinence, especially from food.
- 2
To reduce or limit one's nutrition intake for medical or health reasons, to diet.
- 3
To cause (a person or animal) to abstain, especially from eating.
At 11 weeks of age, all mice were fasted overnight and underwent gallbladder ultrasonography to determine ejection fraction.
noun
- 1
Acronym of focused assessment with sonography for trauma.
- 2
Acronym of firefighter assist and search team.
- 3
Acronym of free advertising-supported streaming television
phrase
- 1
Acronym of facial drooping, arm weakness, speech difficulty, time, a mnemonic for diagnosing a CVA or stroke.
adjective
- 1
An acronym for remembering desirable characteristics for goal-setting: frequently discussed, ambitious, specific, transparent.
interjection
- 1
Ellipsis of stand fast, a warning not to pass between the arrow and the target.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Fast in Spanish, French, German and Portuguese
| Language | Words |
|---|---|
| French | ferme , rapide , profond , en avance , fermement , rapidement |
| German | fest, befestigt, verankert , schnell , geschützt , tief |
| Portuguese | firme, seguro , rápido, veloz , pesado, profundo |
| Spanish | rápido , firmemente , rápidamente , profundamente , ayunar |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does fast come from?
From Middle English fast, fest, from Old English fæst (“firm, secure”), from Proto-West Germanic *fast, from Proto-Germanic *fastuz; see it for cognates and further etymology. The development of “rapid” from an original sense of “secure” apparently happened first in the adverb and then transferred to the adjective; compare hard in expressions like “to run hard”. The original sense of “secure, firm” is now slightly archaic, but retained in the related fasten (“make secure”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).