cosmonaut

noun

cos·​mo·​naut ˈkäz-mə-ˌnȯt 

-ˌnät

: an astronaut of the Soviet or Russian space program

Examples of cosmonaut in a Sentence

Recent Examples on the Web

Its four crew members are NASA astronauts Commander Matthew Dominick, Pilot Michael Barratt, Mission Specialist Jeanette Epps and Roscosmos cosmonaut Mission Specialist Alexander Grebenkin. —Richard Tribou, The Orlando Sentinel, 19 Apr. 2026

This was followed by the Soviet Union launching cosmonaut Yuri Gagarin, who became the first man to circle the globe aboard Vostok I in 1961. —Peter Lucas, Boston Herald, 16 Apr. 2026

Aboard the Vostok 1 spacecraft, Russian cosmonaut Yuri Gagarin became the first human to enter outer space and orbit Earth. —Usa Today, USA Today, 14 Apr. 2026

The three cosmonauts currently living on the orbiting lab — Sergey Kud-Sverchkov, Sergei Mikaev and Andrey Fedyaev — did not participate. —Mike Wall, Space.com, 8 Apr. 2026

Word History

Etymology

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

First Known Use

1955, in the meaning defined above

Rhymes for cosmonaut

• aeronaut
• aforethought
• afterthought
• apricot
• argonaut
• astronaut
• camelot
• coffeepot
• concordat
• entrepot
• flowerpot
• huguenot

Kids Definition

cosmonaut

noun

cos·​mo·​naut ˈkäz-mə-ˌnȯt 

-ˌnät

: a Soviet or Russian astronaut