- any small, soft-rayed fish of the order Cyprinodontes, of warm, fresh or brackish waters in North America, including the killifishes, topminnows, and guppies.
- of, relating to, or resembling the cyprinodonts.
- any small tropical or subtropical soft-finned fish of the mostly marine family Cyprinodontidae, resembling carp but having toothed jaws. The group includes the guppy, killifish, swordtail, and topminnow
- of, relating to, or belonging to the Cyprinodontidae
