Astronaut

google

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1920s: from astro-, on the pattern of aeronaut and aquanaut .

wiktionary

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From astro- +‎ -naut. Coined from Ancient Greek ἄστρον(ástron, “star”) and ναύτης(naútēs, “sailor”).

etymonline

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astronaut (n.)

"space-traveler," 1929 in scientific speculation, popularized from 1961 by U.S. space program, a compound from Greek elements, from astro- "star" + Greek nautes "sailor," from PIE root *nau- "boat." French astronautique (adj.) had been coined 1927 by "J.H. Rosny," pen name of Belgian-born science fiction writer Joseph Henri Honoré Boex, on model of aéronautique, and Astronaut was used in 1880 as the name of a fictional spaceship by English writer Percy Greg in "Across the Zodiac."