Meaning of astro-

astro-

Pronunciation: [key]
  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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.