ˈlüməˌkrōm noun
Etymology: lumi- + -chrome
: a blue fluorescent crystalline compound C 12 H 10 N 4 O 2 that is a derivative of alloxazine, that is formed from riboflavin by ultraviolet irradiation in neutral or acid solution or by the action of microorganisms (as Pseudomonas riboflavina ), and that is found in the urine and milk of ruminants