The term "river horse" is commonly used to refer to the hippopotamus. However, there are several other synonyms that can be used to describe these magnificent creatures. One such synonym is "water horse," which refers to the fact that hippos spend a significant amount of time in water. Another synonym is "river pig," which is often used because of their pig-like appearance and their love for water. Other synonyms for hippopotamus include "sea cow," "Nile horse," and "lake horse." Regardless of the synonym used, it is clear that hippos are fascinating and unique creatures that continue to capture the interest of people all over the world.