The word galaxy is connected to the Greek word gala, which means milk. From that root came the Greek term galaxias, often understood as milky or milk like. This is the source of our modern English word galaxy.
The connection makes sense when you think about the Milky Way. To people looking up at the night sky, it appeared as a pale, cloudy band of light stretching across the darkness. Its soft white look suggested spilled milk, so the Greek name reflected that visual impression.
A simple way to remember it is this:
- gala = milk
- galaxias = milky
- galaxy = a word that grew from that Greek idea
This does not mean every galaxy is named after milk in a direct everyday sense. Rather, the English word developed from the ancient name for the Milky Way, whose appearance inspired the image. So when you hear galaxy, you are hearing a very old comparison to something white and milk like in the sky.