# duplex
## English
### 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.

### Pronunciation

* (US) enPR: do͞o'plĕks, IPA: /ˈdu.plɛks/
* Audio (Southern England):(file)
* Rhymes: -uːplɛks

### Adjective

duplex (not comparable)
* Double; made up of two parts.
** (architecture) Having two floors.
** (architecture) Having two units, divisions, suites, or apartments.
** (metallurgy) Of stainless steel: having a structure containing austenite and ferrite in roughly equal proportions.
*** 2010, Harold M. Cobb, The History of Stainless Steel, Materials Park, O.H.: ASM International, →ISBN, page 189:Duplex stainless steels have been classified according to the first period (1930–1960) and second period (1960–1990). The designations for these duplex alloys in the United States have been primarily according to Unified Numbering System (UNS) numbers in the S3xxx.x series.
* (telecommunications) Bidirectional (in two directions).
    Antonyms: simplex, unidirectional
    duplex telegraphy
* (soil science) Having horizons with contrasting textures.
** 1977, Australian Journal of Botany, volume 25, page 462:Soils are duplex, sandy and solodic. The dominant trees are the stringybark eucalypts […]

#### Hyponyms

(bidirectional):
* full duplex
* half-duplex
* semiduplex

#### Derived terms

* duplexity
* duplex nail
* echoplex
* full duplex
* half-duplex
* heteroduplex
* homoduplex
* interduplex
* intraduplex
* multiduplex
* nonduplex
* semiduplex
* superduplex

#### Related terms

* contraplex
* diplex
* duplex escapement
* duplex lathe
* duplex pumping engine
* duplex querela
* duplex watch

#### Translations
### Noun

duplex (plural duplexes or duplices)
* (US, Canada, Australia) A house made up of two dwelling units.
** 2020, Akwaeke Emezi, The Death of Vivek Oji, Faber & Faber Ltd, page 53:The house had been renovated into a duplex and he’d put in a phone line.
* (US) A dwelling unit with two floors.
* (philately) A cancellation combining a numerical cancellation with a second mark showing time, date, and place of posting.
* (juggling) A throwing motion where two balls are thrown with one hand at the same time.
* (biochemistry) A double-stranded polynucleotide.
* (geology) A system of multiple thrust faults bounded above and below by a roof thrust and floor thrust.
** 1993, David J. Lidke, Jack Burton Epstein, Chester A. Wallace, U.S. Geological Survey Bulletin, page 16:In contrast, the folds in the overlying lithotectonic unit 4 are larger and are cut by a series of faults in a duplex.
** 1995, Robert D. Hatcher, Structural Geology: Principles, Concepts, and Problems, page 211:It has been noted, using a combination of surface geologic and seismic reflection data, that a duplex, although formed in response to movement of a thrust sheet, frequently arches the thrust sheet as the duplex is built by duplication of rocks beneath it […]

#### Related terms

* 2-plex
* diplex
* oligoduplex
* quadruplex
* triplex

#### See also

* bungalow
* maisonette
* rowhouse
* semi-detached
* townhouse

### Verb

duplex (third-person singular simple present duplexes, present participle duplexing, simple past and past participle duplexed)
* To make duplex.
* To make into a duplex.
* (juggling) To make a series of duplex throws.

#### Related terms

* double
* duplicity
* multiplex
* quadruplex
* simplex
* single
* triple
* triplex

### Further reading

* Duplex on Wikipedia.Wikipedia
* Duplex stainless steel on Wikipedia.Wikipedia

## French
### Etymology

Borrowed from Latin duplex, see above.

### Pronunciation

* IPA: /dy.plɛks/
* Audio:(file)
* Audio (Canada):(file)

### Noun

duplex m (plural duplex)
* a link between two points, such as a cable or a wire
* duplex, maisonette (dwelling)

#### Derived terms

* duplexer

### Further reading

* “duplex”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.

## Italian
### Etymology

Unadapted borrowing from Latin duplex.

### Noun

duplex m (invariable)
* (telecommunications) duplex (communications link allowing simultaneous sending and receiving)
* (telephony) party line
* (telephony) telephone or telephone user on a party line
* (metallurgy) duplex process (for refining steel)
* (architecture) two-story residence with separated living and sleeping areas
* (typography) duplex matrix (matrix bearing two signs next to each other)

## Latin
### Etymology

From Proto-Italic *dwipleks, formed from duo (“two”) +‎ -plex (“-fold”).

### Pronunciation

* (Classical Latin) IPA: /ˈdu.pleks/, [ˈd̪ʊpɫ̪ɛks̠] or IPA: /ˈdup.leks/, [ˈd̪ʊpɫ̪ɛks̠]
* (modern Italianate Ecclesiastical) IPA: /ˈdu.pleks/, [ˈd̪uːpleks] or IPA: /ˈdup.leks/, [ˈd̪upleks]

### Adjective

duplex (genitive duplicis, adverb dupliciter); third-declension one-termination adjective
* twofold, two, double
** 44 BCE, Cicero, De Officiis 1.104:Duplex omnīnō est iocandī genus, ūnum illīberāle, petulāns, flāgitiōsum, obscēnum, alterum ēlegāns, urbānum, ingeniōsum, facētum.In all, there are two kinds of joking: one ignoble, irreverent, shameful, obscene; the other elegant, refined, ingenious, witty.(literally, “In all, the kind of joking is twofold: …”)
** 29 BCE – 19 BCE, Virgil, Aeneid 4.469–470:[...] Eumenidum velutī dēmēns videt agmina Penthēus, et sōlem geminum et duplicīs sē ostendere Thēbās [...].Just as the deranged Pentheus sees the ranks of Eumenides, and a twin sun, and Thebes to show herself twofold. (Variant accusative plural: duplicīs. For context, see: The Bacchae.)
* bipartite, cloven
* ambiguous

#### Declension

Third-declension one-termination adjective.
* Sg.Abl. sometimes duplice.

#### Derived terms

* duplicō

#### Descendants

* Galician: dobre (possibly)
* Spanish: doble (possibly)
* → English: duplex
* → French: duplex
* → Italian: duplice, duplex
* → Spanish: dúplex

### References

* “duplex”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
* “duplex”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
* "duplex", 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)
* duplex in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
* Carl Meißner, Henry William Auden (1894) Latin Phrase-Book‎, London: Macmillan and Co. a twofold tradition prevails on this subject: duplex est memoria de aliqua re in two, three columns: agmine duplici, triplici

## Romanian
### Etymology

Borrowed from French duplex.

### Noun

duplex n (plural duplexuri)
* duplex