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

From a cache of images released by NASA this spring that were taken by Artemis II astronauts during a lunar flyby in April. — Ann Manov, Harpers Magazine, 30 June 2026

Once completed, the base would be where astronauts could live and work longterm with the dual objectives of studying the moon while also helping NASA learn how best to send the first humans to Mars. — Eric Lagatta, USA Today, 30 June 2026

An artist's rendering of astronauts, habitats, rovers, power systems and cargo operations near the lunar south pole. — Denise Chow, NBC news, 30 June 2026

Together, those projects aim to establish the hardware and operational experience needed for a sustained American presence on the Moon before astronauts venture onward to Mars. — Aamir Khollam, Interesting Engineering, 30 June 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