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
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
Jackie Wattles 
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The ailing astronaut and the three others returned to Earth more than a month sooner than planned.
—Marcia Dunn, Los Angeles Times, 15 Feb. 2026
The other half of that spacewalk, Christina Koch, is among the four Artemis II astronauts waiting to fly around the moon as early as March.
—Arkansas Online, 14 Feb. 2026
SpaceX launches Crew-12 astronauts With a blinding light, SpaceX's Falcon 9 rocket lifted off on time from Space Launch Complex 40 to carry the four Crew-12 astronauts toward the International Space Station.
—Josh Dinner, Space.com, 14 Feb. 2026
Of the many obstacles to overcome before any Artemis astronauts begin moonwalking, perhaps the most simple yet significant is figuring out what to wear.
—K. R. Callaway, Scientific American, 5 Feb. 2026
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Marcia Dunn, Los Angeles Times, 15 Feb. 2026
The other half of that spacewalk, Christina Koch, is among the four Artemis II astronauts waiting to fly around the moon as early as March.
—Arkansas Online, 14 Feb. 2026
SpaceX launches Crew-12 astronauts With a blinding light, SpaceX's Falcon 9 rocket lifted off on time from Space Launch Complex 40 to carry the four Crew-12 astronauts toward the International Space Station.
—Josh Dinner, Space.com, 14 Feb. 2026
Of the many obstacles to overcome before any Artemis astronauts begin moonwalking, perhaps the most simple yet significant is figuring out what to wear.
—K. R. Callaway, Scientific American, 5 Feb. 2026
See All Example Sentences for astronaut
Cite this Entry
“Astronaut.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronaut. Accessed 18 Feb. 2026.
Copy CitationKids Definition
astronaut
noun
as·tro·naut
ˈas-trə-ˌnȯt
-nät
: a traveler in a spacecraft
astronautic
adjective
ˌas-trə-ˈnȯt-ik
or astronautical
-i-kəl,
-nät-
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