meat loaf vs fish loaf

meat loaf and fish loaf both are nouns.

Word	Noun	Adjective	Verb	Adverb
meat loaf	Yes	No	No	No
fish loaf	Yes	No	No	No

As nouns, fish loaf is a hyponym of meat loaf; that is, fish loaf is a word with a more specific, narrower meaning than meat loaf:

meat loaf: a baked loaf of ground meat
fish loaf: flaked fish baked in a loaf with bread crumbs and various seasonings

meat loaf (noun)	fish loaf (noun)
a baked loaf of ground meat	flaked fish baked in a loaf with bread crumbs and various seasonings