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 Crew-12 astronauts will join NASA's Chris Williams and cosmonauts Sergey Kud-Sverchkov and Sergei Mikaev as a part of ISS Expedition 74, which will eventually transition to Expedition 75 before the end of Crew-12's rotation. —Josh Dinner, Space.com, 28 Jan. 2026

Since 2000, the International Space Station has been continuously occupied by rotating crews of astronauts and cosmonauts. —Jeffrey Kluger, Time, 20 Jan. 2026

Roscomos cosmonaut Aleksandr Gorbunov making his first flight. —Richard Tribou, The Orlando Sentinel, 19 Jan. 2026

After handing off command to Russian cosmonaut Sergey Kud-Sverchkov early Wednesday morning, four astronauts–Zena Cardman and Mike Fincke from NASA, Kimiya Yui from Japan and Oleg Platonov of Russia–entered the SpaceX Dragon capsule Endeavour and safely splashed down in the Pacific Ocean. —Alex Knapp, Forbes.com, 16 Jan. 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