crabmeat vs shellfish

crabmeat and shellfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
crabmeat	Yes	No	No	No
shellfish	Yes	No	No	No

As nouns, shellfish is a hypernym of crabmeat; that is, shellfish is a word with a broader meaning than crabmeat:

crabmeat: the edible flesh of any of various crabs
shellfish: meat of edible aquatic invertebrate with a shell (especially a mollusk or crustacean)

crabmeat (noun)	shellfish (noun)
the edible flesh of any of various crabs	invertebrate having a soft unsegmented body usually enclosed in a shell
	meat of edible aquatic invertebrate with a shell (especially a mollusk or crustacean)