sea horse vs walrus

sea horse and walrus both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea horse	Yes	No	No	No
walrus	Yes	No	No	No

As nouns, sea horse and walrus are synonyms defined as:

sea horse and walrus: either of two large northern marine mammals having ivory tusks and tough hide over thick blubber

Other synonyms of sea horse include seahorse.

sea horse (noun)	walrus (noun)
small fish with horse-like heads bent sharply downward and curled tails; swim in upright position	either of two large northern marine mammals having ivory tusks and tough hide over thick blubber
either of two large northern marine mammals having ivory tusks and tough hide over thick blubber