a splendid assemblage (especially of famous people)
"The red carpet was filled with a galaxy of Hollywood stars waiting to see their new film premiere."
tufted evergreen perennial herb having spikes of tiny white flowers and glossy green round to heart-shaped leaves that become coppery to maroon or purplish in fall
"The galaxy, a tufted evergreen perennial herb with spikes of tiny white flowers and glossy green leaves that turn coppery in fall, adds vibrant color to the garden border."
(astronomy) a collection of star systems; any of the billions of systems each having many stars and nebulae and dust
"`extragalactic nebula' is a former name for `galaxy'"
The Milky Way; the apparent band of concentrated stars which appears in the night sky over earth.
"Last night, I gazed up at the galaxy and marveled at how it looked like a glowing river stretching across the dark horizon."
In plain English: A galaxy is a huge group of billions of stars, planets, and other space objects all held together by gravity.
"The Milky Way is our home galaxy, containing billions of stars including our sun."
Usage: In everyday conversation, use galaxy to refer to any vast system containing billions of stars rather than just our own solar neighborhood. Avoid confusing it with "universe," as a single galaxy is only one component within the much larger cosmos.
the Milky Way Galaxy, from before it was realized that the Milky Way was not the only "galaxy"
"Before astronomers discovered other universes beyond our own, they believed the entire cosmos consisted solely of the stars we now call the Milky Way Galaxy."
The word galaxy comes from the Ancient Greek term for "milky circle," which was shortened to mean the Milky Way. It entered English via Latin and Old French, originally describing the sky's appearance as if it were made of milk.