1 a [count] astronomy : any one of the very large groups of stars that make up the universe
the formation of galaxies
a giant/spiral galaxy
1 b the Galaxy astronomy : the galaxy in which we live : MILKY WAY
2 [count] : a large group of important or well-known people or things
The event was attended by a galaxy of artists.
— galactic /gəˈlæktɪk/ adjective, astronomy