seafood vs food

seafood and food both are nouns.

Word	Noun	Adjective	Verb	Adverb
seafood	Yes	No	No	No
food	Yes	No	No	No

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

seafood: edible fish (broadly including freshwater fish) or shellfish or roe etc
food: any solid substance (as opposed to liquid) that is used as a source of nourishment

Other hypernyms of seafood include solid food.

seafood (noun)	food (noun)
edible fish (broadly including freshwater fish) or shellfish or roe etc	any substance that can be metabolized by an animal to give energy and build tissue
	anything that provides mental stimulus for thinking
	any solid substance (as opposed to liquid) that is used as a source of nourishment