astronaut

noun

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

Examples of astronaut in a Sentence

Recent Examples on the Web
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But this solution was temporary and a more permanent replacement was needed as this antenna ensures that astronauts on the space station can quickly transmit critical information back down to Mission Control back on Earth. Chelsea Gohd, Space.com, 25 Aug. 2026 The spacewalk will feature NASA astronaut Anil Menon and European Space Agency astronaut Sophie Adenot. Eric Lagatta, USA Today, 25 Aug. 2026 The lunar eclipse also may be visible to Hathaway and the nine other people living off the planet — seven astronauts at the International Space Station and three aboard China’s orbiting outpost. Marcia Dunn, Los Angeles Times, 25 Aug. 2026 In April, as the intrepid crew of Artemis II shot around the moon, NASA astronaut Christina Koch snapped a photograph of the distant Earth setting behind the lunar surface. Adam Kovac, Scientific American, 23 Aug. 2026 See All Example Sentences for astronaut

Word History

Etymology

astro- + -naut (in aeronaut)

Note: See note at astronautics.

First Known Use

1928, in the meaning defined above

Time Traveler
The first known use of astronaut was in 1928

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Cite this Entry

“Astronaut.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronaut. Accessed 1 Sep. 2026.

Kids Definition

astronaut

noun
: 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

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