# simplex
## English
### Etymology

The adjective is a learned borrowing from Latin simplex (“plain, simple; single”), ultimately from Proto-Indo-European *sem- (“one; together”) + *meh₁- (“to measure”) + *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 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.)

### Pronunciation

* Adjective and noun (singular form):
** (Received Pronunciation) IPA: /ˈsɪmplɛks/
** (General American) IPA: /ˈsɪmˌplɛks/
** Audio (Southern England):(file)
** Hyphenation: sim‧plex
* Noun (plural form: simplices):
** (Received Pronunciation) IPA: /ˈsɪmplɪsiːz/
** (General American) IPA: /ˈsɪmpləˌsiz/
** Hyphenation: sim‧pli‧ces
* Noun (plural form: simplicia):
** (Received Pronunciation, General American) IPA: /sɪmˈplɪsiə/
** Hyphenation: sim‧pli‧cia

### Adjective

simplex (not comparable)
* (dated) Having a single structure; not composite or complex; undivided, unitary.
    Synonyms: monoplex, uniplex
    Antonym: complex
* (anatomy, historical) Of 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.
    Antonym: duplex
* (computing, telecommunications) Of a circuit or device: involving signals which travel in one direction at a time; unidirectional.
    Antonyms: bidirectional, duplex
    Coordinate terms: full duplex, half-duplex, semiduplex
* (genetics)
** Of a polyploid organism: having one dominant allele at a given locus on all homologous chromosomes.
    Coordinate terms: duplex, nulliplex, triplex
** (archaic or obsolete) Synonym of heterozygous (“of an organism: having two different alleles in a given gene”)
* (linguistics) Of a word: having no (derivational) affixes; simple, monomorphemic, uncompounded.
    Antonym: polymorphemic
* (originally and chiefly US) Of an apartment (or, sometimes, another type of property): having only one floor or storey; single-storey.
    Coordinate terms: duplex, triplex

#### Derived terms

* simplexity

#### Related terms

* crux simplex
* herpes simplex

#### Translations
### Noun

simplex (plural simplexes or (algebraic topology, geometry, linguistics) simplices or simplicia)
* (algebraic topology, geometry) A generalization of a triangle or tetrahedron to an arbitrary dimension, the generalization being the simplest possible convex polytope for a given dimension; more accurately, the convex hull of $n+1$ linearly independent points in $n$-dimensional space.
* (linguistics)
** A word which is not compound and contains no derivational affixes (inflectional affixes are usually disregarded); a monomorphemic word.
    The word weak is a simplex. Its derivative weaken is not.
** (grammar, archaic) In full simplex sentence: in transformational grammar: a simple sentence which is the product of a few transformations; a kernel sentence.
*** 1978, Helga Harries-Delisle, “Contrastive Emphasis and Cleft Sentences”, in Joseph H[arold] Greenberg, editor, Universals of Human Language, volume 4 (Syntax), Stanford, Calif.: Stanford University Press, →ISBN, page 460:The question is: is 139. [“Priexal Vanja. ‘arrived Vanya’”] a simplex or is it a cleft structure in which all 'superfluous' constituents were deleted. […] The only indication that 139. is a simplex is the sentence intonation and the absence of a break between the verb and the subject.A modified version of a paper published in Working Papers on Language Universals (November 1973), number 12, pages 85–144.
* (originally and chiefly US) An apartment (or, sometimes, another type of property) having only one floor or storey; a single-storey property.
    Coordinate terms: duplex, triplex

#### Synonyms

* monoplex

#### Derived terms

* n-simplex
* simplex method

#### Related terms

* simplicial
* simplicial complex

#### Translations
### References

* 1 2 “simplex, adj. and n.”, in OED Online ⁠, Oxford: Oxford University Press, September 2024.
* ↑ “simplex, adj.”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
* ↑ “simplex, n.”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
* ↑ P[ieter] H[endrik] Schoute (1902) “Grundbegriffe [Basic Concepts]”, in Mehrdimensionale Geometrie [Multidimensional Geometry] (Sammlung Schubert; XXXV) (in German), 1st part (Die linearen Räume [The Linear Spaces]), Leipzig, Saxony: G[eorg] J[oachim] Göschen’sche Verlagshandlung, →OCLC, paragraph 8, page 10: “Wir ziehen de namen ‚Simplicissimum‘ das viel kürzere Simplex vor und deuten das Simplex mit $d+1$ Eckpunkten mittels des Symboles $S(d+1)$ an. ― We prefer the name ‘simplicissimum’ to the much shorter simplex and indicate the simplex with $d+1$ vertices using the symbol $S(d+1)$.”
* ↑ Edmund [Frederick] Robertson, John O’Connor (2023 December) “SIMPLEX”, in MacTutor History of Mathematics Archive: Earliest Known Uses of Some of the Words of Mathematics‎, archived from the original on 2023-12-25.

### Further reading

* simplex on Wikipedia.Wikipedia
* simplex (disambiguation) on Wikipedia.Wikipedia

## Latin
### Etymology

From Proto-Italic *sempleks, from the same root as semel +‎ -plex.

### Pronunciation

* (Classical Latin) IPA: /ˈsim.pleks/, [ˈs̠ɪmpɫ̪ɛks̠]
* (modern Italianate Ecclesiastical) IPA: /ˈsim.pleks/, [ˈsimpleks]

### Adjective

simplex (genitive simplicis, comparative simplicior, superlative simplicissimus, adverb simpliciter); third-declension one-termination adjective
* single
* simple, plain, uncompounded
* pure, unmixed
* sincere, naive, frank, open, without guile, guileless, unsuspecting, innocent
** 8 CE, Ovid, Fasti 2.225–226:male crēditis hostī: simplex nōbilitās, perfida tēla cave!You do wrong to trust the enemy: Guileless nobles, beware of treacherous weapons!

#### Declension

Third-declension one-termination adjective.

#### Derived terms

* simplicābilis
* simplicitās
* simpliciter

#### Related terms

* duplex
* simplus
* triplex
* quadruplex

#### Descendants

* Italian: sempice, semprice, semplice (latinized)
* Friulian: sempliç (latinized)
* Sicilian: sìmprici, sìmplici (latinized)
* → Asturian: simple
* → Catalan: simple
* → Dutch: simpel
* → English: simplex
* → Galician: simple
* → German: simpel
** → Norwegian: simpel
* → Middle Low German: simpel
** → Old Swedish: simpel
*** Swedish: simpel
**** → Finnish: simppeli
* → Old French: simple, sinple
** French: simple
*** → Romanian: simplu
** → Middle English: symple, simple
*** Scots: semple
*** English: simple
* → Old Leonese:
** Mirandese: simples
* → Old Galician-Portuguese: simplez
** Portuguese: simples, símplice
* → Romansch: simpel, sempel
* → Spanish: simple
** Chavacano: simple
* → Proto-Brythonic: *sɨml
** Middle Welsh: symyl
*** Welsh: syml

### References

* “simplex”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
* “simplex”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
* "simplex", in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
* simplex in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.

## Romanian
### Etymology

Borrowed from French simplex.

### Noun

simplex n (uncountable)
* simplex