Why are constellations called constellations?

The word "constellation" comes from the Old French "constellacion," which comes from the Late Latin "constellationem."

Here's a breakdown of the word and its Latin roots:

• 
  con- Meaning "with" or "together." This describes the aspect of constellations as being gatherings or patterns of stars.


• 
  stella- Stella or stellae is the word for stars, but a long time ago the same word was used to described planets or other celestial bodies. This word pre-dates technology which allows us to look into the sky and distinguish between stars and planets.


• 
  -tion- This is a suffix for words of Latin origin which describes an action or state of being. 

So, altogether, constellation roughly means "stars which are clustered together."