n. [ L. juglans, -andis, a walnut: cf. F. juglandine. ] (Chem.) An extractive matter contained in the juice of the green shucks of the walnut (Juglans regia). It is used medicinally as an alterative, and also as a black hair dye. [ 1913 Webster ]
n. An alkaloid found in the leaves of the walnut (Juglans regia). [ 1913 Webster ]