pl. (see fish) -·fish·, -·fish·es
any of a family (Cyprinodontidae, order Atheriniformes) of small, freshwater bony fishes used in mosquito control and as bait
Origin of killifishkillie, killifish (; from kill + -ie) + fish
nounpl. killifish or kil·li·fish·es
Any of numerous small fishes of the family Fundulidae and related families of the order Cyprinidontiformes, chiefly inhabiting fresh and brackish waters in warm regions and popular in home aquariums.
Origin of killifishPerhaps kill2 + fish.