astronaut

noun

as·​tro·​naut ˈa-strə-ˌnȯt 

-ˌnät

plural astronauts

: a person whose profession is to travel beyond the earth's atmosphere

NASA on Wednesday introduced the group of astronauts it has chosen for upcoming missions to the moon. The program, called Artemis, aims to send people back to the moon for the first time since the end of NASA's Apollo program in 1972.

—Kenneth Chang

broadly : any person who travels beyond the earth's atmosphere

William Shatner, the 90-year-old actor of "Star Trek" fame, endured a 10-minute, rocket-powered ride to the edge of space … . In that moment, at least one thing became certain: Yes, a nonagenarian can be an astronaut.

—Jackie Wattles

Word Icons

Examples of astronaut in a Sentence

Recent Examples on the Web

The astronauts snapped thousands of photos during their historic pass around the moon, shot video and recorded their personal observations to give researchers insights based on the color sensitivity of the human eye. —William Harwood, CBS News, 12 Apr. 2026

The cuts to science would also affect programs that support human spaceflight, such as heliophysics, a division that helps reaserchers understand the deadly in-space radiation that is a top concern for astronauts. —Jackie Wattles, CNN Money, 11 Apr. 2026

After all, the Artemis 2 astronauts were getting humanity's first up-close looks at the moon in more than 50 years. —Mike Wall, Space.com, 11 Apr. 2026

Space agency officials’ blood pressure was further elevated as experts closely watched the performance of the craft’s heat shield, which astronauts rely on to slow them down and keep temperatures livable. —Noah Haggerty, Los Angeles Times, 11 Apr. 2026

Word History

Etymology

astro- + -naut (in aeronaut)

Note: See note at astronautics.

First Known Use

1928, in the meaning defined above

Rhymes for astronaut

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

Kids Definition

astronaut

noun

as·​tro·​naut ˈas-trə-ˌnȯt 

-nät

: a traveler in a spacecraft

astronautic

ˌas-trə-ˈnȯt-ik

adjective

or astronautical

-i-kəl, 

-nät-

Etymology

from astro- "star, heavens" (derived from Greek astron "star") and -naut (derived from Greek nautēs "sailor," from naus "ship") — related to nausea, nautical see Word History at nausea