cos·​mo·​naut | \ˈkäz-mə-ˌnȯt, -ˌnät\

Definition of cosmonaut 

: an astronaut of the Soviet or Russian space program

Examples of cosmonaut in a Sentence

Recent Examples on the Web

Less than two weeks ago, a Soyuz rocket took off with a Russian cosmonaut and a NASA astronaut riding in a Soyuz capsule. Eric Berger, Ars Technica, "NASA chief says agency plans to launch crew on Soyuz in December," 23 Oct. 2018 Early cosmonauts and astronauts like Yuri Gagarin and John Glenn made only ballistic re-entries to get back down to Earth. Joe Pappalardo, Popular Mechanics, "Ballistic Reentry: How Astronauts Survive a Failed Launch," 11 Oct. 2018 The institute is known for conducting long-term simulations of stays in space using both cosmonauts and ordinary people. Elizabeth Howell,, "Touring Where the Mars-500 'Astronauts' Pretended to Take a Red Planet Journey," 11 July 2018 They're not expected to finish this until at least December, when cosmonauts go outside the station to investigate the leak site from the station exterior. Eric Berger, Ars Technica, "Dramatic footage of Soyuz accident shows rocket booster collision," 1 Nov. 2018 At the institute, most of these people are ordinary folks — not cosmonauts. Elizabeth Howell,, "Touring Where the Mars-500 'Astronauts' Pretended to Take a Red Planet Journey," 11 July 2018 The available Russian sources do not elaborate whether cosmonauts could use the weapon on a spacewalk outside the station. Anatoly Zak, Popular Mechanics, "The Soviet Laser Space Pistol, Revealed," 14 June 2018 Due to budgetary reasons, Roscosmos has reduced the number of cosmonauts on the International Space Station from three to two. Eric Berger, Ars Technica, "Russian editor: Our space program is entering the “Dark Ages”," 9 July 2018 Otherwise with Federatsiya stalled, Russian cosmonauts would depend on NASA to carry its crews to the near-lunar gateway and beyond. Anatoly Zak, Popular Mechanics, "Russia's Soyuz Spacecraft Could Find New Life as a Lunar Taxi," 6 July 2018

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.

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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)

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Last Updated

30 Nov 2018

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The first known use of cosmonaut was in 1955

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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 \

Kids Definition of cosmonaut

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

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Rhyming Dictionary: Words that rhyme with cosmonaut

Spanish Central: Translation of cosmonaut

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

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