Noun | 1. | family Cynoglossidae - tonguefishes fish family - any of various families of fish Heterosomata, order Heterosomata, order Pleuronectiformes - flatfishes: halibut; sole; flounder; plaice; turbot; tonguefishes tonguefish, tongue-fish - left-eyed marine flatfish whose tail tapers to a point; of little commercial value |