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

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Examples of astronaut in a Sentence

Recent Examples on the Web

At age 69, Pettit is NASA’s oldest active astronaut. —Margherita Bassi, Smithsonian Magazine, 11 Dec. 2024

Known across the globe as the stuck astronauts, Butch Wilmore and Suni Williams hit the six-month mark in space on Dec. 5 with two more to go. —Marcia Dunn, The Christian Science Monitor, 6 Dec. 2024

In September, Isaacman teamed with SpaceX to perform the first private spacewalk, a high-risk endeavor reserved for professional astronauts, according to the Associated Press. —Mariyam Muhammad, The Enquirer, 5 Dec. 2024

Despite the challenges of an unplanned extended stay, the two astronauts quickly integrated into life on the ISS, assisting with science experiments and performing routine maintenance, including repairing a malfunctioning toilet and vacuuming air vents. —Jason Fields, Newsweek, 5 Dec. 2024

Word History

Etymology

astro- + -naut (in aeronaut)

Note: See note at astronautics.

First Known Use

1928, in the meaning defined above

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