Merriam-Webster Collegiate Dictionary - gannister

 noun see ganister GANOID  I. adjective  Etymology: ultimately from Greek ganos brightness; akin to Greek gethein to rejoice — more at joy  Date: circa 1847 of, having, or being fish scales consisting of bone and an outer shiny layer resembling enamel; also relating to or being fish with ~ scales  II. noun  Date: circa 1839 a fish (as a sturgeon or gar) with ~ scales