Home › Words › X › xanthorismxanthorismxanthorism means abnormal yellow pigmentation in fish, caused by lack of melanin.Among words judged in Lexicurio's Arena, xanthorism ranks #28,162 of 42,747 for Qualifying.EtymologyFrom xantho- + -ism?nounAbnormal yellow pigmentation in fish, caused by lack of melanin.Definitions & examples from Wiktionary (CC BY-SA 3.0).