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

The film’s opening scene has her wading naked in Hampstead Ponds at night, looking up at the blinking stars and naming the constellations to herself, then closing her eyes as if to let the galaxies above wash over her. — Bilge Ebiri, Vulture, 4 Sep. 2026

Dozens of very luminous stellar cluster members are known, but this area likely has far more stars that are fainter hidden behind a vast smog of opaque dust between the center of the galaxy and the sun. — Phil Plait, Scientific American, 4 Sep. 2026

This hydrogen spans distances of many million light-years, similar to the distance between the Milky Way and our neighbor galaxy, Andromeda. — Robert Lea, Space.com, 4 Sep. 2026

Galaxies are separated into three main categories—spirals, ellipticals, and irregulars. — Popular Science Team, Popular Science, 3 Sep. 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"