molly vs topminnow

molly and topminnow both are nouns.

Word	Noun	Adjective	Verb	Adverb
molly	Yes	No	No	No
topminnow	Yes	No	No	No

As nouns, topminnow is a hypernym of molly; that is, topminnow is a word with a broader meaning than molly:

molly: popular aquarium fish
topminnow: small usually brightly-colored viviparous surface-feeding fishes of fresh or brackish warm waters; often used in mosquito control

Other hypernyms of molly include live-bearer, poeciliid, poeciliid fish.

molly (noun)	topminnow (noun)
popular aquarium fish	small usually brightly-colored viviparous surface-feeding fishes of fresh or brackish warm waters; often used in mosquito control
	freshwater fish of Central America having a long swordlike tail; popular aquarium fish