hard roe vs seafood

hard roe and seafood both are nouns.

Word	Noun	Adjective	Verb	Adverb
hard roe	Yes	No	No	No
seafood	Yes	No	No	No

As nouns, seafood is a hypernym of hard roe; that is, seafood is a word with a broader meaning than hard roe:

hard roe: fish eggs or egg-filled ovary; having a grainy texture
seafood: edible fish (broadly including freshwater fish) or shellfish or roe etc

hard roe (noun)	seafood (noun)
fish eggs or egg-filled ovary; having a grainy texture	edible fish (broadly including freshwater fish) or shellfish or roe etc