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

Cornelis van Zuilen has created a stunning cosmic mosaic of all 110 galaxies, star clusters and nebulas of the Messier catalog — a leviathan effort that took hundreds of hours and many nights of sleeping in his car to complete. — Anthony Wood, Space.com, 11 Oct. 2026

At some point around three billion years after the big bang, some celestial object in a faraway galaxy suddenly went pop and shot out a brief-but-powerful blast of radio waves, lasting just a fraction of a second. — Adam Kovac, Scientific American, 8 Oct. 2026

The Nobel committee said his work was instrumental to the construction of the IceCube Neutrino Observatory in Antarctica, which glimpsed the first high-energy neutrinos from faraway galaxies. — Arkansas Online, 7 Oct. 2026

Halzen’s idea to use Antarctic ice as a giant detector helped create the IceCube observatory, which has captured high-energy neutrinos from distant galaxies and opened a new form of astronomy. — Kostya Manenkov, Los Angeles Times, 6 Oct. 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"