duplex

1 of 3

adjective

du·​plex ˈdü-ˌpleks 

also ˈdyü-

1

a

: having two principal elements or parts : double, twofold

b

: having two complementary polynucleotide strands of DNA or of DNA and RNA

2

: allowing telecommunication in opposite directions simultaneously

duplex

2 of 3

verb

duplexed; duplexing; duplexes

transitive verb

: to make duplex

duplex

3 of 3

noun

: something duplex: such as

a

: a 2-family house

b

: duplex apartment

c

: a duplex molecule of DNA or of RNA and DNA

Did you know?

Duplex can describe a confusing variety of things, depending on the technical field. Most of us use it as a noun: a duplex can be either a two-family house or a two-story apartment. In computer science and telecommunications, duplex (or full-duplex) communication can go in both directions at once, while half-duplex communication can go only one way at a time. In other areas, just translate duplex as "double" and see if the sentence makes sense.

Synonyms of duplex

Adjective

• dual
• binary
• twin

Examples of duplex in a Sentence

Adjective

a duplex apartment with all of the bedrooms on the second floor

Noun

We live in the brick duplex.

Recent Examples on the Web

Adjective

The zone allows the development of single-family homes and duplex-style homes in a condensed area on the property. — Scott Turner | [email protected], al, 3 July 2022

The project consists of 10 duplex-style homes of 1,300 square feet apiece, with three bedrooms, attached two-car garages and private yards. — Joe Tash, San Diego Union-Tribune, 25 Dec. 2022

Verb

Also part of the kit are a lightweight battery, a duplexing antenna that allows both data transmission and wireless power charging, and sensors, none more than 6 millimeters in diameter. — Greg Goth, IEEE Spectrum, 14 Jan. 2024

For scanning and copying, the printer offers both a letter-size flatbed and the 30-sheet reversing ADF, which duplexes by scanning one side of a page, turning it over, and then scanning the other side. — PC Magazine, 28 Aug. 2025

Noun

The other side of the duplex, home to six people, was filled with smoke. — Nathan Pilling, Kansas City Star, 29 June 2026

The duplex is on the market for $22 million. — Abby Montanez, Robb Report, 22 June 2026

Word History

Etymology

Adjective

Latin, from duo two + -plex -fold — more at two, -fold

First Known Use

Adjective

1567, in the meaning defined at sense 1a

Verb

1883, in the meaning defined above

Noun

1922, in the meaning defined above

Phrases Containing duplex

• duplex apartment
• half duplex

Rhymes for duplex

• annex
• annexe
• apex
• aztecs
• carex
• codecs
• codex
• convex
• cusecs
• execs
• fedex
• kleenex

Kids Definition

duplex

1 of 2 adjective

du·​plex ˈd(y)ü-ˌpleks 

1

: being or consisting of two parts : twofold

2

: allowing communication at a distance (as by telephone or television) in opposite directions at the same time

duplex

2 of 2 noun

: something duplex: as

a

: a two-family house

b

: an apartment with rooms on two floors

Medical Definition

duplex

noun

du·​plex ˈd(y)ü-ˌpleks 

: a molecule having two complementary polynucleotide strands of DNA or of DNA and RNA

duplex adjective