Dictionary.com
Thesaurus.com
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

Etymology

Origin of cosmonaut

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

Compare meaning

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

Vocabulary lists containing cosmonaut

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

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

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.

Blue Origin says the last all-female spaceflight was over 60 years ago when Soviet Cosmonaut Valentina Tereshkova became the first woman to travel into space on a solo mission aboard the spacecraft Vostok 6.

From BBC • Apr. 14, 2025

To prepare for his space trip, Maezawa trained for months at the Gagarin Cosmonaut Training Center, near Moscow.

From Washington Post • Dec. 8, 2021

Cosmonaut Oleg Novitsky will portray the ailing space traveler.

From Scientific American • Oct. 5, 2021

The approval Thursday by a commission at the Yuri Gagarin Center for Cosmonaut Training cleared an important hurdle for the movie.

From New York Times • Sep. 16, 2021

Cosmonaut Valentina Tereshkova the first woman ever in space.

From "Tradition" by Brendan Kiely

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.