Simple Definition of duplex

from our Learner's Dictionary

duplex

noun

ˈduːˌplɛks

British ˈdjuːˌplɛks

plural duplexes

US

1

: a building that is divided into two separate homes

We live in the brick duplex.

2

: an apartment with two floors

a duplex penthouse

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“Duplex.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/duplex. Accessed 19 Jun. 2026.

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