The term "sea elephant" refers to the elephant seals that live in the southern hemisphere. Since this marine mammal is specific to the elephant seal species, there are not many synonyms that can replace the term "sea elephant". However, commonly used names are "elephant seal" and "sea lion". Though both share similar characteristics with "sea elephant", elephant seals have a longer and heavier body structure, while sea lions have a sleeker body shape and a mane of fur around the neck area. Other than these, there are no appropriate synonyms that could replace "sea elephant" in a descriptive context.