astronaut

American  

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

noun

• astronauts
  plural

1. a person engaged in or trained for spaceflight.

---

astronaut British  

/ ˈæstrəˌnɔːt /

noun

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

---

astronaut Cultural  

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

---

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

The spacecraft was then hoisted onto a specialized ship, and the four occupants -- Meir, American Jack Hathaway, French astronaut Sophie Adenot and Russian cosmonaut Andrei Fedyaev -- were helped out one by one.

From Barron's ● Oct. 8, 2026

The team is comprised of two Nasa astronauts, a Russian cosmonaut and a Canadian astronaut whose wife is expecting their third child two months into the mission.

From BBC ● Oct. 1, 2026

Scott Tingle, chief of the Astronaut Office at Johnson, likewise highlighted the influence the two astronauts have had on NASA's astronaut corps.

From Science Daily ● Sep. 26, 2026

"Reid and Victor's commitment to exploration, steady leadership, and service to our astronaut corps and our nation have made a lasting impact," said Vanessa Wyche, director of NASA's Johnson Space Center in Houston.

From Science Daily ● Sep. 26, 2026

For an astronaut aboard the spaceship, time stops.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

During the 14-day mission the Apollo 17 astronauts, led by mission commander Eugene Cernan, performed three space walks on the lunar surface.

From BBC ● Oct. 11, 2026

The second investigation will explore one of the Moon's most intriguing possibilities: enormous underground passages that could serve as natural shelters for astronauts.

From Science Daily ● Oct. 8, 2026

NASA’s Low Earth Orbit Program provides reliable access to space while maximizing research and development by partnering with private U.S. companies, including SpaceX, to transport astronauts to and from the International Space Station.

From Los Angeles Times ● Oct. 8, 2026

To unleash our energy, to rebuild our factories, to return our astronauts to the moon and launch a new age of exploration in space.

From The Wall Street Journal ● Oct. 8, 2026

Like the outposts of the American West, Mir became a place for astronauts throughout the world to visit.

From "Women in Space" by Karen Bush Gibson

Random Word

Spin the wheel and learn a new word!

---

Related Words

• cosmonaut
• pilot

---