Fluvioterrestrial is a term that describes a creature that can live in both freshwater and terrestrial environments. However, there are other words that can be used to describe this type of organism. Amphibian is perhaps the most common synonym for fluvioterrestrial species, as these animals are able to live in both water and on land. Other synonyms that can be used include semi-aquatic, aquatic-terrestrial, and aquatic-semi-terrestrial. All of these words describe the same type of creature that can survive in both aqueous and terrestrial ecosystems. Knowing these synonyms can help you expand your vocabulary and better describe these unique species in your writing.