The Collaborative International Dictionary
Marking nut
Marking \Mark"ing\, n. The act of one who, or that which, marks; the mark or marks made; arrangement or disposition of marks or coloring; as, the marking of a bird's plumage.
Marking ink, indelible ink, because used in marking linen.
Marking nut (Bot.), the nut of the Semecarpus Anacardium, an East Indian tree. The shell of the nut yields a blackish resinous juice used for marking cotton cloth, and an oil prepared from it is used for rheumatism.