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.

Definitions of astronaut
  1. noun
    a person trained to travel in a spacecraft
    “the Russians called their astronauts cosmonauts”
    synonyms: cosmonaut, spaceman
    see moresee less
    show 5 examples...
    hide 5 examples...
    Neil Armstrong
    United States astronaut; the first man to set foot on the Moon (July 20, 1969) (1930-)
    Yuri Alekseyevich Gagarin
    Soviet cosmonaut who in 1961 was the first person to travel in space (1934-1968)
    John Herschel Glenn Jr.
    made the first orbital rocket-powered flight by a United States astronaut in 1962; later in United States Senate (1921-)
    Alan Bartlett Shepard Jr.
    astronaut who made the first United States' suborbital rocket-powered flight in 1961 (1923-1998)
    Valentina Vladmirovna Tereshkova
    Soviet cosmonaut who was the first woman in space (born in 1937)
    an astronaut who is active outside a spacecraft in outer space
    type of:
    traveler, traveller
    a person who changes location
Word Family