'topminnow' definitions:

Small usually brightly-colored viviparous surface-feeding fishes of fresh or brackish warm waters; often used in mosquito control [syn: topminnow, poeciliid fish, poeciliid, live-bearer]

Freshwater fish of Central America having a long swordlike tail; popular aquarium fish [syn: swordtail, helleri, topminnow, Xyphophorus helleri]