astronaut

American  

[as-truh-nawt, -not] / ˈæs trəˌnɔt, -ˌnɒt /

noun

• astronauts
  plural

1. a person engaged in or trained for spaceflight.

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astronaut British  

/ ˈæstrəˌnɔːt /

noun

1. a person trained for travelling in space See also cosmonaut

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astronaut Cultural  

1. A crew member of a space mission launched by the United States. (See Apollo program and Mercury program.)

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Other Word Forms

Noun Inflected Forms

• astronauts
  plural

Etymology

Origin of astronaut

1925–30; astro- + (aero)naut, probably via French astronaute; see astronautical

Compare meaning

How does astronaut compare to similar and commonly confused words? Explore the most common comparisons:

• cosmonaut vs. astronaut

Explanation

An astronaut is someone who travels in space. While the term was once reserved for military-trained professionals, recent accessibility of space travel has seen the term astronaut now used to refer to anyone traveling in a spacecraft, including civilians. The word astronaut includes the root naut, from nautes, the Greek word for "sailor." This suffix can be used to create many travel-specific words. For example, the Argonauts were mythical Greek sailors on the ship named the Argo. Astronaut gets the astro from the Greek word astron, meaning "star," making an astronaut a “star sailor.” Russian space explorers took the title cosmonauts, with the cosmo part coming from the Greek for "universe," kosmos, so both have the same meaning.

Example Sentences

See Examples For:

astronaut astronauts

Bosco Ortega, 12, wants to be an astronaut when he grows up but has until now lived in Cairo, where the light pollution means few stars can be seen.

From The Wall Street Journal ● Aug. 12, 2026

He opened a building at the University of Oxford before meeting astronaut Tim Peake at the launch of a space initiative.

From BBC ● Jul. 10, 2026

Winocour has often made films about women balancing their public-facing life with their private selves In 2019’s “Proxima,” Eva Green played an astronaut missing her young daughter.

From Los Angeles Times ● Jun. 26, 2026

US astronaut Christina Koch, the first woman to take part in a lunar mission, was on Wednesday named the winner of a top Spanish prize for having "helped extend the frontiers of humanity".

From Barron's ● Jun. 17, 2026

Two years before, Gagarin had been selected as one of two thousand candidates for a job that did not yet exist—cosmonaut, the Russian term for astronaut.

From "Fallout: Spies, Superbombs, and the Ultimate Cold War Showdown" by Steve Sheinkin

Long before astronauts reach the site, robotic spacecraft will deliver scientific instruments to study conditions on and around the Moon.

From Science Daily ● Aug. 11, 2026

Nasa astronauts Anil Menon and Jessica Meir ventured outside the International Space Station for a spacewalk on Thursday to install mounting hardware.

From BBC ● Aug. 6, 2026

When these materials slam into Earth's magnetic shield, they can knock out satellites, threaten astronauts -- and create colourful auroras in the skies of northern and southern latitudes.

From Barron's ● Aug. 5, 2026

I like baseball, but it’s not like these guys are astronauts, just back from the moon.

From Los Angeles Times ● Jul. 24, 2026

The only thing happening was a lot of radioing between mission control and the astronauts.

From "Gone Crazy in Alabama" by Rita Williams-Garcia

Related Words

• cosmonaut
• pilot