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

Adjective

• binary
• bipartite
• double
• double-barreled
• double-edged
• dual
• twin
• twofold

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

This duplex-style unit is on the top two floors of a 2000 midrise near the Ruggles Orange Line station, Northeastern University, and the Kings’ first home together as a married couple on Northampton Street. —Jon Gorey, BostonGlobe.com, 20 Jan. 2023

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. —IEEE Spectrum, 14 Jan. 2024

Noun

The property also includes a duplex, adding to its income potential. —Colin Burke, Travel + Leisure, 13 Apr. 2025

For single-family homes and duplexes, that would represent an 81% increase over the current year. —David Zahniser, Los Angeles Times, 10 Apr. 2025

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

1833, 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