a small european fresh-water cyprinoid fish (phoxinus laevis, formerly leuciscus phoxinus); sometimes applied also to the young of larger kinds; -- called also minim and minny. the name is also applied to several allied american species, of the genera phoxinus, notropis, or minnilus, and rhinichthys.-any of numerous small american cyprinodont fishes of the genus fundulus, and related genera. they live both in fresh and in salt water. called also killifish, minny, and mummichog.