cosmonaut

noun

cos·​mo·​naut ˈkäz-mə-ˌnȯt How to pronounce cosmonaut (audio)
-ˌnät
: an astronaut of the Soviet or Russian space program

Examples of cosmonaut in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The cosmonauts plonked down on November 19th, 1965 in the Midlands market town of Rugby, a cultural backwater best known for the sport, the school, and wartime poet Rupert Brooke, in that order. — Gabriel Szatan, Pitchfork, 18 Oct. 2026 Only two cosmonauts were originally supposed to fly on this mission, but Soviet politicians pressured the Russian space program to add one more. — Tariq Malik, Space.com, 12 Oct. 2026 In addition, the three members that arrived on a Soyuz include NASA astronaut Anil Menon and cosmonauts Pyotr Dubrov and Anna Kikina. — Richard Tribou, The Orlando Sentinel, 8 Oct. 2026 Also on board are Soyuz MS-29 cosmonauts Pyotr Dubrov and Anna Kikina, along with NASA astronaut Anil Menon. — CBS News, 8 Oct. 2026 See All Example Sentences for cosmonaut

Word History

Etymology

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

First Known Use

1955, in the meaning defined above

Time Traveler
The first known use of cosmonaut was in 1955

Rhymes for cosmonaut

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Browse Nearby Words

cosmology
cosmonaut
cosmonautics
See all Nearby Words

Cite this Entry

“Cosmonaut.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cosmonaut. Accessed 20 Oct. 2026.

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Kids Definition

cosmonaut

noun
cos·​mo·​naut ˈkäz-mə-ˌnȯt How to pronounce cosmonaut (audio)
-ˌnät
: a Soviet or Russian astronaut

More from Merriam-Webster on cosmonaut

Britannica.com: Encyclopedia article about cosmonaut

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