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

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

Rep. Jasmine Crockett and former astronaut Terry Virts in their unsuccessful Senate runs.

From Salon ● Jun. 17, 2026

Backup astronaut Bob Hines will train alongside the primary crew and could replace any astronaut unable to fly the mission.

From Science Daily ● Jun. 11, 2026

If she couldn't be the top astronaut candidate, Jackie decided she would be in charge.

From "Women in Space" by Karen Bush Gibson

China also aims to land astronauts on the moon by 2030.

From The Wall Street Journal ● Jul. 10, 2026

The researchers found that deposits containing mantle material may be spread across portions of the Moon's south polar region, including areas that future Artemis astronauts could potentially visit and study in person.

From Science Daily ● Jun. 22, 2026

Scientists have gained new insight into the dramatic event that created the Moon's largest and oldest known impact crater, a discovery that could help future Artemis astronauts investigate some of the Moon's deepest secrets.

From Science Daily ● Jun. 22, 2026

Its success, which came through trial and failure, has ended U.S. reliance on Russia to transport astronauts to the space station and launch American satellites.

From The Wall Street Journal ● Jun. 12, 2026

Not only was she the first woman in space, but her time in space exceeded the time spent by all of the US astronauts combined.

From "Women in Space" by Karen Bush Gibson

Related Words

• cosmonaut
• pilot