cow shark vs Hexanchus griseus

cow shark and Hexanchus griseus both are nouns.

Word	Noun	Adjective	Verb	Adverb
cow shark	Yes	No	No	No
Hexanchus griseus	Yes	No	No	No

As nouns, cow shark and Hexanchus griseus are synonyms defined as:

cow shark and Hexanchus griseus: large primitive shark widely distributed in warm seas

Other synonyms of cow shark include six-gilled shark.

cow shark (noun)	Hexanchus griseus (noun)
large primitive shark widely distributed in warm seas	large primitive shark widely distributed in warm seas