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Synonyms

duo

1 American  
[doo-oh, dyoo-oh] / ˈdu oʊ, ˈdyu oʊ /

noun

plural

duos

  1. Music. duet.

  2. two persons commonly associated with each other; couple.

  3. two animals or objects of the same sort; two things ordinarily placed or found together; a pair.

    a duo of lovebirds.
duo- 2 American  

  1. a combining form meaning “two,” used in the formation of compound words.

    duologue.
duo 1 British  
/ ˈdjuːəʊ /

noun

  1. music

    1. a pair of performers

    2. another word for duet

  2. a pair of actors, entertainers, etc

  3. informal a pair of closely connected individuals

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
duo- 2 British  

combining form

  1. indicating two

    duotone
"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Usage

What does duo- mean? Duo- is a combining form used like a prefix meaning “two.” It is occasionally used in technical terms.Duo- comes from Greek dýo and Latin duo, both meaning “two.” In fact, English’s own word two is related to these roots! Learn more at our entry at two.

Etymology

Origin of duo1

1580–90; < Italian < Latin: two

Origin of duo-2

Combining form of Greek dýo, Latin duo two

Compare meaning

How does duo compare to similar and commonly confused words? Explore the most common comparisons:

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Data-storage duo Western Digital and Seagate Technology jumped by 10% and 7.6%, respectively.

From Barron's • Apr. 6, 2026

As part of their divorce agreement, the duo split other properties in their portfolio, including a sprawling penthouse apartment on Eleventh Avenue, which they bought for $21.12 million in 2022.

From MarketWatch • Apr. 6, 2026

Brockman took away from the exchange the belief that the duo didn’t want to tell the public about what was happening at the frontiers of AI.

From The Wall Street Journal • Mar. 28, 2026

The duo won Oscars for best picture, director and original screenplay.

From Los Angeles Times • Mar. 26, 2026

Mariela was part of a salsa duo with her older sister and likes to say proudly that she is “one hundred percent Puerto Rican.”

From "Drama High" by Michael Sokolove

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.