Galaxy is a term commonly used to refer to a massive system of stars, dust, and gas held together by gravity. However, there are plenty of alternative words that can be used to describe these astronomical marvels. One such synonym is "cosmos," which refers to the entire universe and all of its components. Another synonym is "star system," which specifically focuses on the collection of stars and other celestial bodies in a particular area. The term "cluster" also refers to a group of galaxies that are held together by gravitational forces. Other synonyms include "nebula," which refers to a cloud of gas and dust that often form new stars, and "Milky Way," which is the name of the galaxy in which our solar system resides.