Etymology
Advertisement
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."

Related entries & more 
Advertisement
astronautics (n.)
"the art of traveling in outer space," 1929; see astronaut + -ics.
Related entries & more 
*nau- 
nāu-, Proto-Indo-European root meaning "boat."

It forms all or part of: aeronautics; aquanaut; Argonaut; astronaut; cosmonaut; nacelle; naval; nave (n.1) "main part of a church;" navicular; navigate; navigation; navy; naufragous; nausea; nautical; nautilus; noise.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit nauh, accusative navam "ship, boat;" Armenian nav "ship;" Greek naus "ship," nautes "sailor;" Latin navis "ship;" Old Irish nau "ship," Welsh noe "a flat vessel;" Old Norse nor "ship."
Related entries & more 
*ster- (2)

Proto-Indo-European root meaning "star." Buck and others doubt the old suggestion that it is a borrowing from Akkadian istar "venus." The source of the common Balto-Slavic word for "star" (Lithuanian žvaigždė, Old Church Slavonic zvezda, Polish gwiazda, Russian zvezda) is not explained.

It forms all or part of: aster; asterisk; asterism; asteroid; astral; astro-; astrobiology; astrobleme; astrognosy; astroid; astrolabe; astrolatry; astrology; astromancy; astronaut; astronomy; AstroTurf; constellation; disaster; Estella; Esther; instellation; interstellar; lodestar; star; stardust; starfish; starlet; starlight; starry; stellar; stellate.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit star-; Hittite shittar, Greek aster "star," with derivative astron; Latin stella, Breton sterenn, Welsh seren "star."

Related entries & more 
spaceman (n.)
1942 in the astronaut sense, from space (n.) + man (n.). Earlier it meant "journalist paid by the length of his copy" (1892). Spacewoman recorded from 1960.
Related entries & more 
Advertisement
cosmonaut (n.)

"a Russian astronaut," 1959, Englishing of Russian kosmonavt, which is ultimately from Greek kosmos (see cosmo-) + nautes "sailor" (from PIE root *nau- "boat"). In reference to space travel, cosmonautic is attested by 1947.

Related entries & more