Plant Pathol. a disease of onions and other plants, characterized by pink, withered roots, caused by a fungus, Pyrenochaeta terrestris.
Pronunciation: (pingk'rOOt", -root"),[key] —n. 1. the root of any of various plants belonging to the genus Spigelia, of the logania family, esp. that of S. marilandica of the U.S., that is used as a vermifuge.
2. any of these plants.