ganoid /ˈɡænoɪd/adjective 2noun 1forms 1 adjective2 •Having a smooth, shining surface, as if polished or enameled: specifically applied to those scales or plates of fishes which are generally of an angular form and composed of a bony or hard horny tissue overlaid with enamel. •Having ganoid scales or plates, as a fish; specifically, of or pertaining to the Ganoidei.In a few minutes the huge beast had been cut up and slabs of him were hanging over a dozen camp fires, together with great scaly ganoid fish which had been speared in the lake. — 1912 noun1 •One of the Ganoidei, a disused taxonomic grouping of fishes, including the bowfin, gars, and sturgeons. formsganoids