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  • astro-
    astro-
    a combining form with the meaning “pertaining to stars or celestial bodies, or to activities, as spaceflight, taking place outside the earth's atmosphere,” used in the formation of compound words.
  • astro–
    astro–
    A prefix that means “star” (as in astrophysics), “celestial body” (as in astronomy), or “outer space” (as in astronaut).

astro-

American  
  1. a combining form with the meaning “pertaining to stars or celestial bodies, or to activities, as spaceflight, taking place outside the earth's atmosphere,” used in the formation of compound words.

    astronautics; astrophotography.


astro- British  

combining form

  1. indicating a heavenly body, star, or star-shaped structure

    astrology

    astrocyte

  2. indicating outer space

    astronautics

"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

astro– Scientific  
  1. A prefix that means “star” (as in astrophysics), “celestial body” (as in astronomy), or “outer space” (as in astronaut).


Usage

What does astro- mean? Astro- is a combining form used like a prefix meaning “related to stars, celestial bodies, and outer space.” It is often used in scientific terms, especially in—you guessed it—astronomy. Astro- is also sometimes used to refer to something that is star-shaped, as in an astrocyte, a type of star-shaped cell in the brain and spinal cord. Astro- comes from the Greek ástron, meaning “star.” The Greek ástron is also related to such words as asteroid and even the star itself. The word astronomy comes from a Greek word that literally (and poetically) means “star-arranging.”What are variants of astro-?When combined with words or word elements that begin with a vowel, astro- becomes astr-.

Etymology

Origin of astro-

< Greek, combining form of ástron a star, constellation, akin to astḗr star; aster, -aster 2

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.

See Examples For:

Soccer is still silent about the vote because they're too busy planting astro- turf at stadiums where the Women's Team will play.

From New York Times Feb. 22, 2016

No group of people live harder and more intimately with this truth than the long-serving crews of astro- and cosmonauts, the expeditionary campers-in-the-stars who man the International Space Station.

From Forbes Feb. 25, 2015

Cady is one of the leading lights in a brightening field known as astro- or exobiology--the study of how life could form elsewhere in the universe.

From Time Magazine Archive

Antipater, who had an anniversary feast every year upon his birth-day, needed no astro- logical revolution to know what day he should die on.

From Religio Medici, Hydriotaphia, and the Letter to a Friend by Browne, Thomas, Sir

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