Why was the solar system given its name?

Answer 1

The term "the solar system" is not really a proper name, any more than, for example, calling "the galaxy" such. If Earth had only one ocean we might call it "the ocean" and not have a proper name to distinguish it from other oceans since we only had one. Our galaxy does have a proper name, "The Milky Way" but the solar system is just derived from the term "solar", meaning, 'pertaining to the Sun' - which is particularly appropriate since the definition of the solar system is usually taken to mean the region in which the Sun's gravitational force is dominant. Some might say "Sol" is the proper name of the Sun but this is not commonly used (except, perhaps, in fiction).