duplex
/ˈdu.plɛks/
"duplex" is a 6-letter English headword indexed on PlainSpell.
The verdict
“duplex” is a moderately-common English word, ranked #24,433 in English word frequency and used as an adjective.
- #24,433
- frequency rank, English
- 6
- letters
- 9
- tracked misspellings
- 3
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Double; made up of two parts.
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 | duplex |
| Language | English |
| Part of speech | Adjective |
| IPA | /ˈdu.plɛks/ |
| Letters | 6 |
| Frequency rank | #24,433 |
| Misspellings tracked | 9 |
| Confusable pairs | 3 |
| Source | Wiktionary (kaikki.org) |
Where “duplex” sits in English frequency
Spelling & Dictionary Insight
The English entry for duplex is 6 letters long, classified as an adjective, and transcribed in the International Phonetic Alphabet as /ˈdu.plɛks/. Corpus data places it at rank #24,433 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 5 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 9 likely wrong-spelling variants for duplex, with forms such as "dduplex", "dpulex", and "dulpex". 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 3 confusable-pair relationships, "dupe", "duper", "Dudley", where similar look or sound leads writers to substitute one word for another in context.
Etymologically, the entry records: PIE word *dwóh₁ Borrowed from Latin duplex (“double, two-fold”), from duo (“two”) + plico (“fold together”); compare the roots of διπλόος (diplóos, “double”); compare also πλέκω (plékō, “twist, braid”). By surface analysis, duo- + -plex. The correct English form is duplex, spelled D-U-P-L-E-X.
Definition
- 1Double; made up of two parts.
- 2Double; made up of two parts.
- 3Double; made up of two parts.
- 4Bidirectional (in two directions).
- 5Having horizons with contrasting textures.
Etymology
PIE word *dwóh₁ Borrowed from Latin duplex (“double, two-fold”), from duo (“two”) + plico (“fold together”); compare the roots of διπλόος (diplóos, “double”); compare also πλέκω (plékō, “twist, braid”). By surface analysis, duo- + -plex.
This word in other languages
Common misspellings
Also misspelled as: dduplex,dpulex,dulpex,dupelx,duplexx,dupllex,duplxe,dupplex,udplex
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of duplex - 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
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Using “duplex”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is D-U-P-L-E-X - every other letter order is a misspelling in standard orthography.
- Say it as /ˈdu.plɛks/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “dupe” - see the side-by-side comparison. duplex vs dupe
- 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.