swordtail vs topminnow

swordtail and topminnow both are nouns.

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

As nouns, swordtail and topminnow are synonyms defined as:

swordtail and topminnow: freshwater fish of Central America having a long swordlike tail; popular aquarium fish

Other synonyms of swordtail include helleri, Xyphophorus helleri.

swordtail (noun)	topminnow (noun)
freshwater fish of Central America having a long swordlike tail; 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