astro-

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-

combining_form

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

   astrocyte

   astrology

2. indicating outer space

   astronautics

astro–

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

Word History and Origins

Origin of astro-¹

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

Word History and Origins

Origin of astro-¹

from Greek, from astron star

Example Sentences

A celebration of Playstation's 30-year history and a reminder of the joy that gaming can bring, Astro Bot could be the game to beat this year.

From BBC

This year's Game Awards shortlist has been announced, with Astro Bot and Final Fantasy VII Rebirth picking up the most nominations.

From BBC

The recent release of Astro Bot and the announcement of Sony's upgraded £699 PlayStation 5 Pro has reignited some long-running debates among gamers.

From BBC

Astro Bot could be just the recipe Sony has been looking for.

From BBC

But in a quiet year for first-party PlayStation releases, Astro Bot has received some of the highest review scores of 2024 and some critics say it’s one of Sony’s best in ages.

From BBC

Words That Use astro-

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-.

Examples of astro-

You have likely heard of the word (and even dreamed of becoming an) astronaut.

As we know, astro- means “star.” How about -naut? It ultimately comes from the Greek naútēs, meaning “sailor.” Astronaut literally—and again, so poetically— translates to “star sailor.”

What are some other words that use the combining form astro-?

• astroarchaeology
• astroblastoma
• astrobleme
• astrobotany
• astrochemistry
• astrocompass
• astrocytoma
• astrodome
• astrodynamics
• astrology (via the equivalent form of astro- in Greek)
• astrogate
• astrogeology
• astroglia
• astrograph
• astrometry
• astrophysics

Learn about some other applications of astro- in our Vocab Builder article on Astroturf.

Similar to astro- are the combining forms cosmo- and cosm- (think cosmos). Learn more about these forms in our Words That Use cosmo- and Words That Use cosm- articles.

Break it down!

If navigating refers to moving ships in the water or planes in the sky, then what is astrogating?