Home › Words › G › gambusiagambusiagambusia means any of several livebearing freshwater fish, of the genus Gambusia, that feed on the larva of mosquitos and are used to control them.EtymologyFrom the genus name.nounAny of several livebearing freshwater fish, of the genus Gambusia, that feed on the larva of mosquitos and are used to control them.Definitions & examples from Wiktionary (CC BY-SA 3.0).