Definitions for killifishˈkɪl iˌfɪʃ
Random House Webster's College Dictionary
kil•li•fishˈkɪl iˌfɪʃ(n.)(pl.)-fish; -fish•es.
any small freshwater fish of the family Cyprinodontidae, used as bait and for mosquito control.
Ref: Also called topminnow.
any of several livebearers.
Origin of killifish:
1805–15, Amer.; killi- (perh. kill2+-y2+fish
small mostly marine warm-water carp-like schooling fishes; used as bait or aquarium fishes or in mosquito control
Any of a number of tiny fish in the Cyprinodontiformes order of ray-finned fish.
any one of several small American cyprinodont fishes of the genus Fundulus and allied genera. They live equally well in fresh and brackish water, or even in the sea. They are usually striped or barred with black. Called also minnow, and brook fish. See Minnow