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Synonyms

cosmonaut

American  
[koz-muh-nawt, -not] / ˈkɒz məˌnɔt, -ˌnɒt /

noun

  1. a Russian or Soviet astronaut.

cosmonaut British  
/ ˈkɒzməˌnɔːt /

noun

  1. an astronaut, esp in the former Soviet Union

"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
cosmonaut Cultural  

  1. A crew member of a space mission launched by the former Soviet Union.

Other Word Forms

  • cosmonautic adjective
  • cosmonautically adverb

Etymology

Origin of cosmonaut

1955–60; cosmo- + (aero)naut, representing Russian kosmonávt

Compare meaning

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Vocabulary lists containing cosmonaut

Elements of the Universe: Cosm, Cosmo ("Universe")

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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.

In March 1995 Valeri Polyakov, a Russian cosmonaut, returned to Earth after a record 14 consecutive months in space.

From The Wall Street Journal • Feb. 19, 2026

This late uncertainty is just the most recent twist for the SpaceX Crew-12 mission, which includes Americans Jessica Meir and Jack Hathaway, French astronaut Sophie Adenot and Russian cosmonaut Andrey Fedyaev.

From Barron's • Feb. 5, 2026

Fedyaev will make history as the first cosmonaut to fly twice on Dragon.

From Science Daily • Feb. 2, 2026

Fitting for an artist who once put himself through the physical rigors of cosmonaut training, the show feels like a dialogue between opposing forces — boundlessness and constraint, presence and absence.

From Los Angeles Times • Oct. 16, 2025

During the political upheaval of the uncertain 1990s, the third female Russian cosmonaut was in training.

From "Women in Space" by Karen Bush Gibson

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.