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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To this end, Invisible Rainbows and The Edge of Space-Time both offer a correction to the exclusion of scientists and astronauts who were not straight white men, especially in their choices of interlocutors. Literary Hub, 10 Aug. 2026 Later this August, 2026, China is launching a mission to extract water ice at the lunar South Pole to help astronauts live at the base, SCMP reports. Maria Mocerino, Interesting Engineering, 9 Aug. 2026 That scenario is part of everyday life for astronauts aboard the International Space Station (ISS). Sundeep Venkatesan, Scientific American, 9 Aug. 2026 By 1976, 12 NASA astronauts had walked on the moon, the last two on Apollo 17 in 1973 and the Space Race was over. Tariq Malik, Space.com, 9 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

Browse Nearby Words

Cite this Entry

“Astronaut.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronaut. Accessed 14 Aug. 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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