fast

Less common meanings

6. 6
   a deep sleepadjectivearchaic

   Deep and sound, said of sleep; completely asleep, said of a person.

   Similardeep, sound

   Oppositelight

   Note

   Sleep borrows the old "firm" meaning here. Fast asleep means asleep and hard to shift, not asleep quickly, though a modern ear can hear it the second way. Shakespeare's Macbeth applies the word to sleep itself. Today most of this idea lives in the phrase fast asleep, where fast works as an adverb. Source

   Checked 1 Nov 2026 · 2 facts

   • The sleep sense derives from fast meaning firmly fixed or anchored, rather than quickly. en.wiktionary.org
   • Shakespeare's Macbeth uses fast to describe sleep itself; the Gentlewoman speaks the words. shakespeare-navigators.ewu.edu
7. 7
   tightlyadverb

   In a firm or secure manner, so as not to be moved.

   The climbers held fast to the cliff as the wind rose.

   The boat's anchor caught and held fast in the rocky bed.

   UsageFast follows the verb in hold fast, stick fast, and stand fast. Stand fast means refuse to give way.

   Similarsecurely, firmly, tightly

   Oppositeloosely

   Note

   It thrives after verbs of holding and binding, as in hold fast and tied fast; Swift's Gulliver is "tyed fast." It also appears in the proverb Shakespeare quotes in The Merchant of Venice: "Fast bind, fast find." Source

   Checked 1 Nov 2026 · 3 facts

   • Jonathan Swift wrote Gulliver's Travels. en.wikipedia.org
   • Gulliver describes himself as tyed fast, with that spelling. en.wikisource.org
   • The Merchant of Venice contains the proverb Fast bind, fast find; Shylock speaks it. folgerdigitaltexts.org
8. 8
   clock aheadadjective

   Indicating a time ahead of the correct or scheduled time.

   Her watch was fast, so she reached the platform far too early.

   I keep my bedroom clock fifteen minutes fast so that I'm never late for the morning bus.

   UsageThe amount goes before fast: my watch is five minutes fast.

   Similarahead

   Oppositebehind, slow

   Note

   Clocks and watches are its natural subjects. A fast watch shows a time ahead of the real one, and its opposite is slow. After be, the word is this adjective: the hall clock is always fast. After run or go, it becomes the matching adverb: my watch is running fast.

9. 9
   adverb

   In a manner ahead of the correct time, as a timepiece running quickly.

   The station clock has been running fast for a week.

   My grandfather's pocket watch runs fast, gaining a few minutes every week, so he resets it each Sunday.

   Similarahead

   Oppositebehind

10. 10
    sleep soundlyadverb

    Deeply and soundly, especially in reference to sleeping.

    Despite the thunder rattling the windows, he stayed fast asleep all night.

    We tiptoed past the guest room, where Grandpa was already fast asleep in his armchair.

    UsageAlmost always fast asleep, meaning deeply asleep.

    Similardeeply

    Oppositelightly

    Note

    Today this adverb lives almost entirely in fast asleep, where it strengthens asleep much as deeply or soundly would. Older writing also put it after the verb, as in sleeping fast, a pattern that now sounds archaic. Both keep the old firmness of sound sleep. Source

    Checked 3 Nov 2026 · 2 facts

    • Older writing used fast after the verb sleep, including sleeping fast. gutenberg.org
    • The sleep expressions preserve the older sense of firmness. en.wiktionary.org
11. 11
    loyaladjective

    Steadfast and unwavering in feeling or loyalty, now mostly in set phrases like fast friends.

    Despite the distance between them, the two stayed fast friends for decades.

    The two women met in a hospital waiting room years ago and have been fast friends ever since.

    Similarfirm, close, loyal, steadfast, staunch

    Oppositefickle, disloyal, inconstant

    Note

    Loyalty understood as firmness of feeling. The old "secure" meaning is applied here to people and their attachments. Source

    Checked 1 Nov 2026 · 1 fact

    • The loyalty sense belongs to the older meaning of firmness or security. en.wiktionary.org
12. 12
    not fadingadjective

    Not running or fading when exposed to damaging conditions such as water or strong light; permanent.

    The dye proved fast even after dozens of hot washes.

    Printers test whether the inks stay fast under harsh sunlight.

    Similarpermanent, fixed, indelible, stable, lasting

    Oppositefugitive, impermanent

    Note

    Firmness again, this time of color: a fast dye stays put in the cloth. Writers on textiles name the threat with to, as in fast to water. Kax Wilson's A History of Textiles (1979) observes that early mineral pigments "were generally not fast to water." The compound colorfast says the same thing in one word. Source

    Checked 30 Oct 2026 · 3 facts

    • Kax Wilson wrote A History of Textiles. openlibrary.org
    • A History of Textiles was published in 1979. openlibrary.org
    • Wilson's book contains the quoted wording about early mineral pigments. en.wiktionary.org
13. 13
    quick surfaceadjective

    Of a surface or condition, causing unusually rapid play or action.

    Grass courts are notoriously fast, rewarding players with powerful serves.

    The greens were fast that afternoon, sending putts well past the hole.

    Similarquick, slick

    Oppositeslow

14. 14
    light-sensitiveadjective

    Of photographic film, highly sensitive to light; of a lens, having a large maximum aperture, so allowing short exposures.

    The photographer switched to a fast film to freeze motion in the gloomy arena.

    A fast lens with a wide aperture excels in available-light photography.

    Similarsensitive, high-speed, bright

    Oppositeslow

    Note

    The speed here belongs to the exposure, not to the film. Film that is more sensitive to light needs less of it, so a fast film or a fast lens allows shorter exposures and shooting in dim conditions. A slower one demands more light or more time. The same logic explains why photographers describe sensitivity as a speed at all. Source

    Checked 31 Oct 2026 · 7 facts

    • The speed refers to the time needed to complete an exposure. en.wikipedia.org
    • More sensitive film requires less light. kodak.com
    • Fast film permits shorter exposures and photography in lower light. nikonusa.com
    • A fast lens permits shorter exposures. en.wikipedia.org
    • A large lens aperture helps photography in dim conditions. nikonusa.com
    • Slower film or a slower lens requires more illumination or a longer exposure, other conditions being equal. nikonusa.com
    • Sensitivity is called speed because more sensitive emulsions need less exposure time. en.wikipedia.org
15. 15
    adjectivedated

    Firmly fixed or held in place; secure and not easily moved or taken.

    The old gatepost remained fast despite years of storms.

    As the tide turned, the fishermen made their lines fast to the iron rings along the harbor wall.

    UsageMostly survives in make fast: make the rope fast to the ring.

    Similarsecure, firm, fixed, tight, immovable

    Oppositeloose, insecure

16. 16
    wild livingadjectivedated

    Living a wild, pleasure-seeking life, or behaving in a sexually free way, especially for one's age.

    She fell in with a fast crowd of gamblers and spendthrifts.

    You're alone with her at last / And you're waiting 'til you think the time is right / Cause you've heard she's pretty fast / And you're hoping that she'll give you some tonight.

    1979, Doug Fieger, Good Girls Don't

    Similarwild, dissolute, loose

    Note

    A word of disapproval first found in the eighteenth century, now dated, and applied to both men and women. George W. Bungay glosses a fast man as "a lover of wine." By the time of Dorothy L. Sayers's The Queen's Square (1933), the character who calls a young woman fast admits she sounds old-fashioned. Said of a girl or young woman, it often meant too forward or too free for her age. Source

    Checked 31 Oct 2026 · 6 facts

    • The sense dates from the eighteenth century. en.wiktionary.org
    • George W. Bungay used 'a lover of wine' to explain 'a fast man'. en.wiktionary.org
    • Dorothy L. Sayers wrote 'The Queen's Square'. fadedpage.com
    • The character who calls the young woman fast acknowledges being thought old-fashioned. fadedpage.com
    • Lady Hermione anticipates that her listener thinks her old-fashioned. fadedpage.com
    • Applied to a girl or young woman, fast could mean unusually mature or sexually free for her age. en.wiktionary.org
17. 17
    close behindadverb

    Right next to or directly after something in place or time; very close.

    The hounds came fast on the heels of the fleeing fox.

    Her cottage lay fast by the harbor wall, within reach of the spray.

    Similarclose, hard, near, right

    Oppositefar

    Note

    Here the word measures distance, not speed. It usually comes in two phrases: fast by, meaning close beside, and fast on someone's heels, meaning close behind. Fast on our heels is easily misheard as the "quickly" adverb, but the riders are close behind, whatever their pace. Source

    Checked 1 Nov 2026 · 1 fact

    • This sense denotes proximity rather than speed. en.wiktionary.org
18. 18
    nounBritishcountable

    A train that calls at only some of the stations it passes, typically the principal ones.

    Commuters crowded onto the fast to avoid the dozen stops on the slow service.

    She missed the fast and had to take a stopping train instead.

    Similarexpress

    Oppositelocal

    Note

    British railway talk turns the adjective into a noun: commuters catch the fast. Its counterparts are the slow train and the stopper, which call at every station along the way. The more general word for the same service is express.

19. 19
    verb

    To cause a person or animal to abstain from food, especially before a procedure.
20. 20
    adjective

    Of a free neutron, having high kinetic energy, typically around one million electron volts or more, as just after release by fission or fusion and before being slowed.
21. 21
    interjection

    Ellipsis of stand fast: on an archery range, a shouted order to stop shooting and keep clear of the line of fire.