sleeper
/ˈsliːpə(ɹ)/
"sleeper" is a 7-letter English headword indexed on PlainSpell.
The verdict
“sleeper” is a moderately-common English word, ranked #15,911 in English word frequency and used as a noun.
- #15,911
- frequency rank, English
- 7
- letters
- 10
- tracked misspellings
- 12
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Someone who sleeps.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | sleeper |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈsliːpə(ɹ)/ |
| Letters | 7 |
| Frequency rank | #15,911 |
| Misspellings tracked | 10 |
| Confusable pairs | 12 |
| Source | Wiktionary (kaikki.org) |
Where “sleeper” sits in English frequency
Spelling & Dictionary Insight
The English entry for sleeper is 7 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈsliːpə(ɹ)/. Corpus data places it at rank #15,911 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 14 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 10 likely wrong-spelling variants for sleeper, with forms such as "lseeper", "seleper", and "sleeepr". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 12 confusable-pair relationships, "sleeve", "sleeps", "sleepy", and more, a pairing that trips writers up because the two words share enough sound or shape to blur together.
Etymologically, the entry records: From Middle English sleper, equivalent to sleep + -er. The correct English form is sleeper, spelled S-L-E-E-P-E-R.
Definition
- 1Someone who sleeps.
- 2That which lies dormant, as a law.
- 3A spy, saboteur, or terrorist who lives unobtrusively in a community until activated by a prearranged signal; may be part of a sleeper cell.
- 4A small starter earring, worn to prevent a piercing from closing.
- 5A railway sleeping car.
- 6A sleeper hold.
- 7Something that achieves unexpected success after an interval of time.
- 8Any of family Odontobutidae of goby-like bottom-feeding freshwater fish.
- 9A nurse shark (family Ginglymostomatidae).
- 10A type of pajama for a person, especially a child, that covers the whole body, including the feet.
- 11An 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.
- 12A sedative.
- 13A bet placed on the gambling table and then forgotten about by the gambler.
- 14A pod or similar device containing a person in cryosleep.
Etymology
From Middle English sleper, equivalent to sleep + -er.
Synonyms
This word in other languages
Common misspellings
Also misspelled as: lseeper,seleper,sleeepr,sleeperr,sleepper,sleepre,slepeer,sleper,slleeper,ssleeper
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of sleeper - counted as single-character edits (an insertion, a deletion, or a substituted letter). The larger the bar, the easier the typo is to spot; one-edit slips are the ones that sneak past readers.
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
How do you spell "sleeper"?
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Using “sleeper”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is S-L-E-E-P-E-R - every other letter order is a misspelling in standard orthography.
- Say it as /ˈsliːpə(ɹ)/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “sleeve” - see the side-by-side comparison. sleeper vs sleeve
- Browse more English words and confusable pairs in the same reference. English words
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.