molly vs poeciliid

molly and poeciliid both are nouns.

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

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

molly: popular aquarium fish
poeciliid: 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 fish, topminnow.

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