simplex
/ˈsɪmplɛks/
"simplex" is a 7-letter English headword indexed on PlainSpell.
The verdict
“simplex” is a moderately-common English word, ranked #30,229 in English word frequency and used as an adjective.
- #30,229
- frequency rank, English
- 7
- letters
- 11
- tracked misspellings
- 6
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Having a single structure; not composite or complex; undivided, unitary.
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 | simplex |
| Language | English |
| Part of speech | Adjective |
| IPA | /ˈsɪmplɛks/ |
| Letters | 7 |
| Frequency rank | #30,229 |
| Misspellings tracked | 11 |
| Confusable pairs | 6 |
| Source | Wiktionary (kaikki.org) |
Where “simplex” sits in English frequency
Spelling & Dictionary Insight
The English entry for simplex is 7 letters long, classified as an adjective, and transcribed in the International Phonetic Alphabet as /ˈsɪmplɛks/. Corpus data places it at rank #30,229 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 7 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 11 likely wrong-spelling variants for simplex, with forms such as "ismplex", "simlpex", and "simmplex". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. It also participates in 6 confusable-pair relationships, "simply", "simple", "sample", and more, a pairing that trips writers up because the two words share enough sound or shape to blur together.
Etymologically, the entry records: The adjective is a learned borrowing from Latin simplex (“plain, simple; single”). The first part, sim-, comes from Proto-Indo-European *sem-, *sm̥- (“one; together”). The second part, -plex, may be from *pleḱ- (“to weave”). The noun is derived from the adj… The correct English form is simplex, spelled S-I-M-P-L-E-X.
Definition
- 1Having a single structure; not composite or complex; undivided, unitary.
- 2Of an eye: (supposedly) having pigment on only the posterior surface of the iris and not the anterior surface, and thus appearing blue; this was later found to be inaccurate, as eye colour is due to the amount of pigment in the anterior surface of the iris; also, of eye pigmentation: present only on the posterior surface of the iris; and of a person: having eyes with this form of pigmentation.
- 3Of a circuit or device: involving signals which travel in one direction at a time; unidirectional.
- 4Of a polyploid organism: having one dominant allele at a given locus on all homologous chromosomes.
- 5Synonym of heterozygous (“of an organism: having two different alleles in a given gene”).
- 6Of a word: having no (derivational) affixes; simple, monomorphemic, uncompounded.
- 7Of an apartment (or, sometimes, another type of property): having only one floor or storey; single-storey.
Etymology
The adjective is a learned borrowing from Latin simplex (“plain, simple; single”). The first part, sim-, comes from Proto-Indo-European *sem-, *sm̥- (“one; together”). The second part, -plex, may be from *pleḱ- (“to weave”). The noun is derived from the adjective. The plural forms simplices and simplicia are learned borrowings from Latin simplicēs (masculine or feminine) and simplicia (neuter), respectively plural forms of simplex. Noun noun sense 1 (“generalization of a triangle or tetrahedron to an arbitrary dimension”) was apparently coined by the Dutch mathematician Pieter Hendrik Schoute (1846–1913) as a short version of Simplicissimum in Mehrdimensionale Geometrie (in German, 1902). (In his pioneering works on algebraic topology, the French mathematician Henri Poincaré (1854–1912) had previously introduced the concept, but not the actual term simplex.)
Common misspellings
Also misspelled as: ismplex,simlpex,simmplex,simpelx,simplexx,simpllex,simplxe,simpplex,sipmlex,smiplex,ssimplex
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of simplex - 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 "simplex"?
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Using “simplex”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is S-I-M-P-L-E-X - every other letter order is a misspelling in standard orthography.
- Say it as /ˈsɪmplɛks/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “simply” - see the side-by-side comparison. simplex vs simply
- 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.