cos·​mo·​naut | \ ˈkäz-mə-ˌnȯt How to pronounce cosmonaut (audio) , -ˌnät \

Definition of cosmonaut

: an astronaut of the Soviet or Russian space program

Examples of cosmonaut in a Sentence

Recent Examples on the Web In September 2015, cosmonaut Gennady Padalka arrived back on Earth for the last time. Matt Blitz, Popular Mechanics, "We Already Know How to Build a Time Machine," 17 Dec. 2020 During his mission, McArthur’s main crew mate was Russian cosmonaut Valeri Tokarev. Samantha Masunaga, Los Angeles Times, "Earthlings and astronauts chat away, via ham radio," 23 Dec. 2020 Roscosmos has not yet committed to flying a cosmonaut on the US vehicle. Eric Berger, Ars Technica, "Russia’s space chief is hopping mad over most recent US restrictions," 22 Dec. 2020 But in April, Soviet cosmonaut Yuri Gagarin became the first human to orbit the Earth—a world-wide sensation. Edward Kosner, WSJ, "‘Operation Moonglow’ Review: The Rockets’ Red Scare," 19 Nov. 2020 To his right is cosmonaut Aleksey Ovchinin, from northwest Yaroslavl. Joe Pappalardo, Popular Mechanics, "How a Russian Rocket Launch Failed Spectacularly In Just 118 Seconds," 3 Sep. 2020 Yuri, a little cosmonaut knitted by Kud-Sverchkov's wife Olga, accompanied them during their October launch. Ashley Strickland, CNN, "Russian spacewalk will prepare space station for new module," 18 Nov. 2020 Mixed crews would ensure at least one astronaut or cosmonaut on board the station at all times, regardless of the sudden departure of a Soyuz or commercial crew ship, to operate their nation's systems. William Harwood, CBS News, "SpaceX launches 4 astronauts to space station, beginning new era for NASA," 16 Nov. 2020 The failure of the second launch sealed the Soviet's fate in the moon race and raised the question if a Soviet cosmonaut would ever walk on the moon. Anatoly Zak, Popular Mechanics, "Why Didn't the Soviets Ever Make It to the Moon?," 9 Nov. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cosmonaut.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of cosmonaut

1955, in the meaning defined above

History and Etymology for cosmonaut

Russian kosmonavt, from Greek kosmos + Russian -navt (as in aeronavt aeronaut)

Keep scrolling for more

Learn More about cosmonaut

Time Traveler for cosmonaut

Time Traveler

The first known use of cosmonaut was in 1955

See more words from the same year

Statistics for cosmonaut

Last Updated

14 Jan 2021

Cite this Entry

“Cosmonaut.” Dictionary, Merriam-Webster, Accessed 23 Jan. 2021.

Keep scrolling for more

More Definitions for cosmonaut


How to pronounce cosmonaut (audio)

English Language Learners Definition of cosmonaut

: an astronaut in the space program of Russia or the former Soviet Union


cos·​mo·​naut | \ ˈkäz-mə-ˌnȯt How to pronounce cosmonaut (audio) \

Kids Definition of cosmonaut

: an astronaut in the space program of Russia or the former Soviet Union

More from Merriam-Webster on cosmonaut

Nglish: Translation of cosmonaut for Spanish Speakers Encyclopedia article about cosmonaut

Comments on cosmonaut

What made you want to look up cosmonaut? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Slippery Words Quiz—Changing with the Times

  • ducreux self portrait yawning
  • What is an earlier meaning of nice?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

 AlphaBear 2

Spell words. Make bears.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!