galaxy

noun

gal·​axy ˈga-lək-sē 

plural galaxies

1

a

often Galaxy : milky way galaxy

—used with the

b

: any of the very large groups of stars and associated matter that are found throughout the universe

2

a

: an assemblage of brilliant or notable persons or things

a galaxy of artists

b

: world sense 11

… remained galaxies apart on the issue …

—Newsweek

Did you know?

The system of stars that includes our sun looks, in the night sky, like a broad band of light. We call this band the Milky Way. The idea of the whiteness of the Milky Way being similar to that of milk is much older than the English language, however. Galaxias, the Greek word for the Milky Way, was derived from the Greek gala, “milk.” English galaxy, derived from Greek galaxias, was not used until the 19th century as a generic term for other star systems as well as the one in which we live.

Synonyms of galaxy

• world

Examples of galaxy in a Sentence

The event was attended by a galaxy of artists.

they're a galaxy apart when it comes to politics

Recent Examples on the Web

On Saturday, April 18, comet Pan-STARRS will get to within a couple of degrees of galaxy NGC 7814, a distant edge-on spiral. —Jamie Carter, Space.com, 13 Apr. 2026

The European Space Agency telescope is designed to make a 3D map of the universe by looking at billions of galaxies up to 10 billion light years away across one third of the sky. —Richard Tribou, The Orlando Sentinel, 11 Apr. 2026

Only when stars and galaxies started forming from all that hydrogen was there enough light and heat to reionize some of the hydrogen atoms, making those growing cosmic structures visible to our telescopes. —Joseph Howlett, Scientific American, 8 Apr. 2026

However, evidence from a team at Germany’s Max Planck Institute for Radio Astronomy now offers the first clear look at a pair of supermassive black holes at the heart of a distant galaxy. —Andrew Paul, Popular Science, 8 Apr. 2026

Word History

Etymology

Middle English galaxias, galaxie, borrowed from Late Latin galaxias, borrowed from Greek galaxías (probably originally conjoined with kýklos "wheel"), from galakt-, stem of gála "milk" (going back to Indo-European *glkt-, attested elsewhere only in Latin lact-, lac "milk," Armenian kat'n) + -ias, noun suffix, especially of natural phenomena

First Known Use

15th century, in the meaning defined at sense 1a

Phrases Containing galaxy

• elliptical galaxy
• Milky Way galaxy
• radio galaxy
• satellite galaxy
• Seyfert galaxy
• spiral galaxy

Kids Definition

galaxy

noun

gal·​axy ˈgal-ək-sē 

plural galaxies

1

: milky way galaxy

2

: one of the very large groups of stars and other matter that are found throughout the universe

Etymology

Middle English galaxie "the Milky Way," from Latin galaxias (same meaning), from Greek galaxias "Milky Way," from galakt-, gala "milk"