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

This combination of isolation, altitude and temperature is what makes the site so scientifically valuable as a training ground for scientists and astronauts — and as a test site for equipment and rovers. —Rosanna Philpott, CNN Money, 24 Oct. 2025

Kelly, a former NASA astronaut who flew on Discovery twice, and Warner also released a video on social media contrasting chopping vegetables to chopping up the space shuttle. —ArsTechnica, 23 Oct. 2025

These futuristic, transparent habitats could become the first real homes for astronauts on the Moon. —Kurt Knutsson, FOXNews.com, 23 Oct. 2025

The launch vehicle, regarded as the world's largest and most powerful rocket, is the centerpiece of Musk's vision of sending the first humans to Mars, and is also critical in NASA's plans to return astronauts to the moon's surface. —Eric Lagatta, USA Today, 23 Oct. 2025

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