[ gal-uhk-see ]
/ ˈgæl ək si /
Save This Word!

noun, plural gal·ax·ies.
  1. a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space.
  2. (usually initial capital letter) Milky Way.
any large and brilliant or impressive assemblage of persons or things: a galaxy of opera stars.
There's an ocean of difference between the way people speak English in the US vs. the UK. Are your language skills up to the task of telling the difference? Let's find out!
Question 1 of 7
True or false? British English and American English are only different when it comes to slang words.

Origin of galaxy

1350–1400; Middle English galaxie, galaxias<Medieval Latin galaxia,galaxias, ultimately <Greek galaxías kýklos the Milky Way; see galacto-
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use galaxy in a sentence

British Dictionary definitions for galaxy (1 of 2)

/ (ˈɡæləksɪ) /

noun plural -axies
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 ellipseFormer names: island universe, extragalactic nebula Related adjective: galactic
a splendid gathering, esp one of famous or distinguished people

Word Origin for galaxy

C14 (in the sense: the Milky Way), from Medieval Latin galaxia, from Latin galaxias, from Greek, from gala milk; related to Latin lac milk

British Dictionary definitions for galaxy (2 of 2)

/ (ˈɡæləksɪ) /

the Galaxy the spiral galaxy, approximately 100 000 light years in diameter, that contains the solar system about three fifths of the distance from its centreAlso known as: the Milky Way System See also Magellanic Cloud
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for galaxy

[ gălək-sē ]

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. See more at active galaxy. See also elliptical galaxy irregular galaxy lenticular galaxy spiral galaxy.
the Galaxy. The Milky Way.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for galaxy


A large, self-contained mass of stars.

notes for galaxy

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

notes for galaxy

The universe contains billions of galaxies.

notes for galaxy

The sun belongs to the galaxy called the Milky Way.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.