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

The other astronauts on board the mission include Sophie Adenot of the European Space Agency, and Roscosmos cosmonaut Andrey Fedyaev, according to NASA. —Seth Jacobson, wickedlocal.com, 17 Feb. 2026

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, 16 Feb. 2026

The Crew-12 mission includes two NASA astronauts, Jessica Meir and Jack Hathaway, French astronaut Sophie Adenot, and Russian cosmonaut Andrey Fedyaev. —Lydia Calitri, NPR, 14 Feb. 2026

The quartet is joining up with three other spaceflyers on the ISS — NASA's Chris Williams and cosmonauts Sergey Kud-Sverchkov and Sergei Mikaev. —Mike Wall, Space.com, 14 Feb. 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