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astronaut

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

noun

  1. a person engaged in or trained for spaceflight.

astronaut British  
/ ˈæstrəˌnɔːt /

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
astronaut Cultural  

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

Etymology

Origin of astronaut

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

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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.

Mission controllers in Houston, however, were able to work with astronaut Christina Koch to put in a fix.

From The Wall Street Journal • Apr. 2, 2026

In 1995, during his first year at the military college, Hansen met one of his heroes: Canadian astronaut Chris Hadfield.

From BBC • Apr. 2, 2026

"The moon is a witness plate to our entire solar system's formation," said astronaut Koch in a press conference over the weekend.

From Barron's • Apr. 1, 2026

Behind them will be Christina Koch and Jeremy Hansen, a Canadian fighter pilot turned astronaut.

From BBC • Mar. 31, 2026

Two things sprang to mind as I watched one astronaut on the moon, and then another astronaut running, hopping, and frolicking on the moon.

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

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.