Why is split pea soup called soup?

Split pea soup is called soup because it fits the basic definition of soup:

* It's a liquid food. The peas are cooked in a broth or stock, creating a liquid base.

* It contains ingredients other than just liquid. Split peas, vegetables, and often meat or ham are added to the broth, providing substance and flavor.

So, while split pea soup might be thicker than some other soups, its ingredients and preparation methods classify it as a soup.