morindin \mo*rin"din\, n. (Chem.) A yellow dyestuff ({C27H30O14}) extracted from the root bark of an East Indian plant ({Morinda citrifolia}) or from the bark of {Coprosma australis}. The substance is also found in the fruit of the {Morinda citrifolia}, called noni, which is touted by some merchants to have a stimulatory effect on the immune system. It is a disaccharide derivative of anthracenedione. [1913 Webster +PJC]