n. The act or operation of digging or sinking a hole or pit.n. The act or operation of placing in a pit or in pits: as, the pitting of potatoes; the pitting of hides.n. A pit, mark, or hollow depression on the surface, such as that left on the flesh by a pustule of the smallpox.n. A number of such pits considered collectively; a collection of pitmarks.n. In botany, the state or condition of being pitted.n. A corrosion of the inner surface of steam-boilers, whereby the metal becomes gradually covered with small cavities.n. A corrosion of the bottom of iron ships.n. In geology, the excavation of small pits in a surface of rock, usually by some process of solution.