astronaut
Americannoun
noun
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:
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.
Vocabulary lists containing astronaut
Occupations
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Elements of the Universe: Aster, Astro ("Star")
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
astro, aster
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Astronaut Jeremy Hansen said the moment should "challenge this generation and the next, to make sure this record is not long-lived."
From Barron's • Apr. 7, 2026
After her first spaceflight, she served as deputy chief of NASA's Astronaut Office.
From Science Daily • Jan. 22, 2026
NS-31 Astronaut Lauren Sánchez celebrates a successful mission to space.
From Salon • Apr. 17, 2025
McDowell’s TV credits also include “The Astronaut Wives Club,” “Chase the Lion” and “I Am Athlete.”
From Los Angeles Times • Aug. 6, 2024
Astronaut is Greek for “star voyager” or “star sailor.”
From "Women in Space" by Karen Bush Gibson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
