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• galaxy
  galaxy

  noun
• Galaxy
  Galaxy

  noun

  the spiral galaxy, approximately 100 000 light years in diameter, that contains the solar system about three fifths of the distance from its centre See also Magellanic Cloud

galaxy

American  

[gal-uhk-see] / ˈgæl ək si /

noun

galaxies plural

1. Astronomy.

   1. a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space.

   2. Often the galaxy or the Galaxy the system of stars in which the earth and the sun are located; the Milky Way.

2. any large and brilliant or impressive assemblage of people or things.

   Guests at the party included a whole galaxy of opera stars.

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galaxy ¹ British  

/ ˈɡæləksɪ /

noun

1. Former names: island universe.   extragalactic nebula.  any of a vast number of star systems held together by gravitational attraction in an asymmetric shape (an irregular galaxy ) or, more usually, in a symmetrical shape (a regular galaxy ), which is either a spiral or an ellipse

2. a splendid gathering, esp one of famous or distinguished people

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Galaxy ² British  

/ ˈɡæləksɪ /

noun

1. Also known as: the Milky Way System.  the spiral galaxy, approximately 100 000 light years in diameter, that contains the solar system about three fifths of the distance from its centre See also Magellanic Cloud

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galaxy Scientific  

/ găl′ək-sē /

1. Any of numerous large-scale collections of stars, gas, and dust that make up the visible universe. Galaxies are held together by the gravitational attraction of the material contained within them, and most are organized around a galactic nucleus into elliptical or spiral shapes, with a small percentage of galaxies classed as irregular in shape. A galaxy may range in diameter from some hundreds of light-years for the smallest dwarfs to hundreds of thousands of light-years for the largest ellipticals, and may contain from a few million to several trillion stars. Many galaxies are grouped into clusters, with the clusters themselves often grouped into larger superclusters.

2. See more at active galaxy See also elliptical galaxy irregular galaxy lenticular galaxy spiral galaxy

3. the Galaxy. The Milky Way.

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galaxy Cultural  

1. A large, self-contained mass of stars.

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Discover More

A common form for galaxies is a bright center with spiral arms radiating outward.

The sun belongs to the galaxy called the Milky Way.

The universe contains billions of galaxies.

Other Word Forms

Inflected Forms

noun

• galaxies
  plural

Etymology

Origin of galaxy

First recorded in 1350–1400; Middle English galaxie, galaxias, from Medieval Latin galaxia, galaxias, ultimately from Greek galaxías kýklos “the Milky Way”; see cycle, galacto-

Explanation

A galaxy is a collection of stars and planets that are held together by gravity. In a galaxy, the celestial bodies rotate around a central object. The Earth's galaxy is known as the Milky Way. Our solar system, made up of the Sun and the planets that encircle it, is a tiny part of that galaxy. A galaxy can also refer to a gathering of a lot of sparkly people –– like celebrities or sports stars. What gravity holds this galaxy together? Usually cameras.

Example Sentences

Through telescopes or long-exposure photography, however, they reveal spectacular details including glowing clouds of gas, dying stars, and stellar nurseries scattered throughout our galaxy.

From Science Daily • Jun. 3, 2026

One of Roman's primary surveys will look far beyond that range, examining stars through the Milky Way's densely packed central bulge and extending all the way to the far side of the galaxy.

From Science Daily • Jun. 1, 2026

M88 is classified as an active galaxy because a supermassive black hole at its center is actively consuming gas and dust.

From Science Daily • Jun. 1, 2026

Roman, however, will search largely unexplored areas of the Milky Way, offering a much broader view of planetary systems across our galaxy.

From Science Daily • Jun. 1, 2026

Smaller and smaller went the details of her vision, until she could see each particle, spinning around itself like a tiny galaxy.

From "The Girl Who Drank the Moon" by Kelly Barnhill