sleeper

sleep·er
S1L1E1E1P3E1R1
/ˈsliːpə(ɹ)/

noun

Someone who sleeps.

“She's a heavy sleeper: it takes a lot to wake her up.”

Less commonScrabble 9

Meanings

sleeper1

nounsleeper (plural sleepers)

plural sleepers

  1. Someone who sleeps.

    She's a heavy sleeper: it takes a lot to wake her up.

    2 more examples

    I'm a light sleeper: I get woken up by the smallest of sounds.

    Waveless mattresses are for those who prefer a more stationary [night's sleep]; semiwaveless for those who want a slight rocking motion, and free-flow for sleepers who want the feel of a boat. All beds come with temperature controls, and king- and queen-size models offer dual controls.

    1986 August 28, Patricia Leigh Brown, “17 YEARS OF THE WATER BED: A SOCIAL HISTORY; CHECKING OUT REFINEMENTS”, in The New York Times, archived from the original on 03 Feb 2018
  2. That which lies dormant, as a law.

    The object of these provisions is to prevent insertion of "jokers" or "sleepers" in bills and securing passage under the false color of the title.

    1958, Duncan Leroy Kennedy, Bill drafting, page 12
    1 more example

    Therefore let penal laws, if they have been sleepers of long, or if they be grown unfit for the present time, be by wise judged confined in the execution […]

    1625, Francis [Bacon], “Of Judicature”, in The Essayes […], 3rd edition, London: […] Iohn Haviland for Hanna Barret, →OCLC
  3. A spy, saboteur, or terrorist who lives unobtrusively in a community until activated by a prearranged signal; may be part of a sleeper cell.

    We are up against the pros; and pros who have been involved in this kind of activity for many years. […] The public apathy today is disturbing — few realize, Mr. Chairman, that there are sleepers in this country and we know that they are able to manipulate at will behind the scenes.

    1969, United States Congress, Departments of Treasury and Post Office and Executive Office Appropriations for 1970: Hearings, (91st Congress, First Session, parts 2-3), page 479

    Synonyms: sleeper agent

  4. A small starter earring, worn to prevent a piercing from closing.
    1 more example

    His skull earring had been replaced by a small gold sleeper. […] Fiona, who also had pierced ears, remarked on his sleeper. “Doesn’t Wilton allow pierced ears?” she asked. “No way!” said Leslie. “Rules about everything. But I wanted to keep my options open, as you might say. No one’s made me take it out yet. […]”

    1984, Diana Wynne Jones, Fire and Hemlock
  5. A railway sleeping car.

    We spent a night on an uncomfortable sleeper between Athens and Vienna.

    1 more example

    It is realised that the old Pullman standard sleeper, with its convertible "sections", each containing upper and lower berths, and with no greater privacy at night than the curtains drawn along both sides of a middle aisle, has had its day.

    1944 November and December, “"Duplex Roomette" Sleeping Cars”, in Railway Magazine, page 324
  6. furnitureA sleeper hold.

    Detailed floral stripe on sofas, sleepers and loveseats with correlating provincial print on double ruffle trim.

    1980, Montgomery Ward, “‘Country Charm’ slipcovers and all the important accessories”, in Fall & Winter ’80, Chicago, Ill., →OCLC, page 1278, column 1
    2 more examples

    The Slobproof line — made with a softer, more supple version of Crypton Ms. Weiner developed with the manufacturer — includes sectionals, sleepers, sofas and chairs (the Jacob chair, above left, is $975).

    2010 April 22, Joyce Cohen, “Slobproof Sofas and Chairs”, in The New York Times, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 26 Apr 2010

    The mechanism is far easier to maneuver than those found in classic sleepers (see video below). That’s because you’re lifting only two of the three panels—the third glides up or down against the back of the couch and easily slides into position whether you’re opening or closing the sleeper.

    2024 December 12, Joshua Lyon, “The Best Sleeper Sofas”, in Wirecutter, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 12 Dec 2024
  7. Something that achieves unexpected success after an interval of time.

    A box-office bomb when it first came out, the film was a sleeper, becoming much more popular decades after being released.

    1 more example

    For example, the [racehorse] trainer may have tipped a betting syndicate that he is about to unleash a sleeper […]

    1968, Marvin B. Scott, The Racing Game, page 160

    Synonyms: sleeper hit

  8. Any member of the family Odontobutidae of goby-like bottom-feeding freshwater fish.

    Synonyms: sleeper goby

  9. A nurse shark (family Ginglymostomatidae).
  10. businessA type of pajama for a person, especially a child, that covers the whole body, including the feet.

    Aaron, Devin, and Laura looked so comfy in their sleepers.

  11. slangautomotiveAn automobile which has been internally modified to excess, while retaining a mostly stock appearance in order to fool opponents in a drag race, or to avoid the attention of the police.

    Antonyms: cop magnet, rice burner, racecar

  12. slangmedicineA sedative.

    At least a couple of weeks since I last slept, / Kept takin' sleepers, but now I keep myself pepped.

    1995, “Insomnia”, in Reverence, performed by Faithless
    1 more example

    Major trials show an association between the use of 'sleepers' known as benzodiazepines and an increased risk of developing dementia.

    2017 October 21, Ellie Cannon, “ASK DR ELLIE: Why do I have itchy arms in the autumn and is insomnia a warning of Dementia?”, in Daily Mail, London: DMG Media, →ISSN, →OCLC, archived from the original on 07 Nov 2017
  13. slanggamblingA bet placed on the gambling table and then forgotten about by the gambler.
  14. literatureA pod or similar device containing a person in cryosleep.
verbsleeper (third-person singular simple present sleepers, present participle sleepering, simple past and past participle sleepered)

present singular third person sleepers · participle present sleepering · participle past sleepered · past sleepered

  1. rareTo mark a calf by cutting its ear.

    I expect there ain't a trick to maverickin' and sleeperin' and changin' a brand he don't know.

    1963, Jack Schaefer, Monte Walsh, page 81

sleeper2

nounsleeper (plural sleepers)

plural sleepers

  1. UKrail transportA railroad tie.

    Government surveyors set to work, importing hundreds of Indian coolies, thousands of donkeys and camels, and the millions of sleepers required for this monstrous engineering project.

    2009, Michela Wrong, It’s Our Turn to Eat: The Story of a Kenyan Whistle Blower
    3 more examples

    "There," she said to herself, looking into the shadow of the carriage, at the sand and coal dust which covered the sleepers— "there, in the very middle, and I will punish him and escape from everyone and from myself."

    1901 [1878], chapter 31, in Constance Garnett, transl., Anna Karenina, translation of Анна Каренина (Anna Karenina) by Leo Tolstoy, part 7

    The train, minus the three abandoned trucks, again proceeded at a slow pace, with a pump trolley doing pilot ahead ; this was very necessary as a great many sleepers were found to have been burnt underneath the fishplates.

    1901, George Gipps, The Fighting in North China (up to the Fall of Tientsin City), Shanghai: Kelly and Walsh, →OL, page 40

    I should imagine that the smooth riding and the quietness of the diesel or electric cab, coupled with the effect on the eyes of endless successions of sleepers disappearing from sight immediately under the driver's eyes, might in time have a soporific effect, so that the company of a second man, who can assist in signal observations when he is not at work in the engine cab, seems highly desirable in such conditions.

    1961 July, Cecil J. Allen, “Locomotive Running Past and Present”, in Trains Illustrated, page 401

    Synonyms: tie

  2. businessA structural beam in a floor running perpendicular to both the joists beneath and floorboards above.
  3. nauticalA heavy floor timber in a ship's bottom.
  4. nauticalThe lowest, or bottom, tier of casks.

Sleeper3

proper nounSleeper (plural Sleepers)

plural Sleepers

Synonyms & antonyms

nounA spy, saboteur, or terrorist who lives unobtrusively in a community until activated by a prearranged signal; may be part of a sleeper cell.

nounSomething that achieves unexpected success after an interval of time.

nounAny member of the family Odontobutidae of goby-like bottom-feeding freshwater fish.

Similar
sleeper goby

nounAn automobile which has been internally modified to excess, while retaining a mostly stock appearance in order to fool opponents in a drag race, or to avoid the attention of the police.

nounA railroad tie.

Similar

More synonyms by meaning

nouna rester who is sleeping

Similar
Broader

nounone of the cross braces that support the rails on a railway track

nouna passenger car that has berths for sleeping

nountropical fish that resembles a goby and rests quietly on the bottom in shallow water

Similar
sleeper goby
Broader
percoid fishpercoidpercoidean

Synonym sets from Open English WordNet, CC BY 4.0.

Origin

sleeper · noun, verb

  1. Middle Englishsleper
  2. Englishsleeper

From Middle English sleper, equivalent to sleep + -er.

Full word history & related roots →

sleeper · noun

Compare Norwegian sleip (“a sleeper (a timber); as adjective, slippery, smooth”). See slape.

Full word history & related roots →

Translations

Bulgarian спящ човек, траверса
  • спящ човек (spjašt čovek)someone who sleeps
  • траверса (traversa)structural timber in a floor perpendicular to the joists and floorboards
Catalan dormilega
  • dormilegasomeone who sleeps
Dutch slaper
  • slapersomeone who sleeps
Esperanto dormanto
  • dormantosomeone who sleeps
Finnish nukkuja, kuollut kirjain
  • nukkujasomeone who sleeps
  • kuollut kirjainthat which lies dormant, as a law
  • nukkuva agenttispy, saboteur or terrorist waiting to be activated
  • harjoituskorvarengasstarter earring
  • rohmutokkofreshwater fish of the family Odontobutidae
  • unihaalaritype of pajamas that covers the whole body
French dormeur
  • dormeursomeone who sleeps
German Schläfer, Schläfer
  • Schläfersomeone who sleeps
  • Schläferspy, saboteur or terrorist waiting to be activated
  • Strampelanzugtype of pajamas that covers the whole body
  • Lagerholzstructural timber in a floor perpendicular to the joists and floorboards
  • Futterholzstructural timber in a floor perpendicular to the joists and floorboards
  • Unterlageholzstructural timber in a floor perpendicular to the joists and floorboards
  • Lagerholzstructural beam at the bottom of a wall, a roof framework or a similar structure
  • Schwellestructural beam at the bottom of a wall, a roof framework or a similar structure
  • Schwellenholzstructural beam at the bottom of a wall, a roof framework or a similar structure
  • Lagerbalkenstructural beam at the bottom of a wall, a roof framework or a similar structure
  • Fußschwellestructural beam at the bottom of a wall, a roof framework or a similar structure
  • Unterlageholzstructural beam at the bottom of a wall, a roof framework or a similar structure
  • Mauerlattestructural beam at the bottom of a wall, a roof framework or a similar structure
  • Fußpfettestructural beam at the bottom of a wall, a roof framework or a similar structure
  • Fusspfettestructural beam at the bottom of a wall, a roof framework or a similar structure
Hungarian alvó
  • alvósomeone who sleeps
Irish codlatóir, fáinne cluaise simplí
  • codlatóirsomeone who sleeps
  • fáinne cluaise simplístarter earring
Korean 자는 사람
  • 자는 사람 (janeun saram)someone who sleeps
Latin dormītor
  • dormītorsomeone who sleeps
Polish śpiący
  • śpiącysomeone who sleeps
Portuguese dorminhoco, dorminhoca
  • dorminhocosomeone who sleeps
  • dorminhocasomeone who sleeps
Russian со́ня, спя́щий аге́нт
  • со́ня (sónja)someone who sleeps
  • спя́щий аге́нт (spjáščij agént)spy, saboteur or terrorist waiting to be activated
  • крот (krot)spy, saboteur or terrorist waiting to be activated
  • диверса́нт (diversánt)spy, saboteur or terrorist waiting to be activated
  • сабота́жник (sabotážnik)spy, saboteur or terrorist waiting to be activated
Spanish dormilón, pijama con los pies
  • dormilónsomeone who sleeps
  • pijama con los piestype of pajamas that covers the whole body
  • durmienterung on a train track
Swahili mlalaji
  • mlalajisomeone who sleeps
Swedish sovare
  • sovaresomeone who sleeps
Turkish uykucu
  • uykucusomeone who sleeps
Welsh cysgadur
  • cysgadursomeone who sleeps

Rhymes & wordplay

Rhymes with sleeper

All rhymes →

Anagrams

Cite this entry
APA

sleeper. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/sleeper

MLA

“sleeper.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/sleeper. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “sleeper,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/sleeper.

Source: sleeper on Wiktionary, CC BY-SA 4.0.