1. (of fish scales) hard and bony with a shiny enamellike surface.
2. of, relating to, or characteristic of certain bony fishes, such as the sturgeon and the gar, that have armourlike scales consisting of bony plates covered with layers of dentine and enamel.
3. a ganoid fish.
Etymology: from French ganoïde, from Greek ganos ”brightness, gladness”, from ganusthai, “to rejoice”.