seafood vs hard roe

seafood and hard roe both are nouns.

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

As nouns, hard roe is a hyponym of seafood; that is, hard roe is a word with a more specific, narrower meaning than seafood:

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

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