as·​tro·​naut ˈa-strə-ˌnȯt How to pronounce astronaut (audio)
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 In the film, Sandler plays Jakub Prochazka, an astronaut on a solo mission to Jupiter. Eric Andersson, Peoplemag, 22 Feb. 2024 Intuitive Machines The agency's goal is to help kickstart development of new technologies and to collect data that will be needed by Artemis astronauts planning to land near the moon's south pole later this decade. William Harwood, CBS News, 22 Feb. 2024 Planned missions under the Artemis program will allow researchers to learn more about the pressures astronauts will face during the journey to Mars. Nick Kanas, The Conversation, 21 Feb. 2024 But the perfect touchdown of the Eagle lunar lander by NASA astronaut Neil Armstrong was anything but easy. Ashley Strickland, CNN, 17 Feb. 2024 Related: Exercise helps astronauts cope with side effects of spaceflight. Nicholas Stfleur, STAT, 16 Feb. 2024 Sandra Bullock and George Clooney deliver performances that are both grounded and gripping, playing astronauts adrift in the aftermath of a catastrophic accident. Travis Bean, Forbes, 16 Feb. 2024 Instead, such a creation could find its way into emergency food supplies in regions struck by famine or natural disaster, as well as potentially within astronaut and military rations. Andrew Paul, Popular Science, 14 Feb. 2024 The government agency has been working on returning astronauts to the moon as part of the $2.6 billion Artemis program. Tori Latham, Robb Report, 13 Feb. 2024 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'astronaut.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

Dictionary Entries Near astronaut

Cite this Entry

“Astronaut.” Dictionary, Merriam-Webster, Accessed 2 Mar. 2024.

Kids Definition


as·​tro·​naut ˈas-trə-ˌnȯt How to pronounce astronaut (audio)
: a traveler in a spacecraft
or astronautical

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

More from Merriam-Webster on astronaut

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