silverfish vs goldfish

silverfish and goldfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
silverfish	Yes	No	No	No
goldfish	Yes	No	No	No

As nouns, goldfish is a hypernym of silverfish; that is, goldfish is a word with a broader meaning than silverfish:

silverfish: a silvery variety of Carassius auratus
goldfish: small golden or orange-red freshwater fishes of Eurasia used as pond or aquarium fishes

Other hypernyms of silverfish include Carassius auratus.

silverfish (noun)	goldfish (noun)
a silvery variety of Carassius auratus	small golden or orange-red freshwater fishes of Eurasia used as pond or aquarium fishes
silver-grey wingless insect found in houses feeding on book bindings and starched clothing