galaxy

noun

gal·​axy ˈga-lək-sē 

plural galaxies

1

a

often capitalized : 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

• 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 a planet with 10 percent carbon dioxide, a technological civilization would need to last for at least 280,000 years for humanity to have even one neighbor in the galaxy living at the same time. —Rupendra Brahambhatt, Interesting Engineering, 13 Sep. 2025

The central young star, or protostar, weighing as much as 10 of our suns, is located 15,000 light-years away in the outer reaches of our galaxy. —Eric Lagatta, USA Today, 12 Sep. 2025

The winners of the 2025 ZWO Astronomy Photographer of the Year Award have been revealed, showcasing a spectacular selection of night sky images that reveal the majesty of ancient galaxies, nebulas, stellar cities and of course, Earth's moon. —Anthony Wood, Space.com, 12 Sep. 2025

Dust is ubiquitous in the modern Universe, appearing in nearly all galaxies. —Ethan Siegel, Big Think, 12 Sep. 2025

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"