These words are compared as they denote an unfilled space within a solid body. Hole is the most general word, and also the most ambiguous; a hole in a stocking goes through it, a hole in a piece of timber may or may not go through, a hole in the ground does not go through the earth, but may be narrow or wide, shallow or very deep. Hollow and cavity refer to an empty space within something otherwise solid or filled; of the two, cavity is somewhat more learned or formal except for its popular use to describe a hole in a tooth: the pleural cavity in which the lungs are situated; the abdominal cavity . Hollow is frequently used of any depression or concavity in a surface: the hollows of the sea. Pit denotes primarily certain large natural cavities , especially in the ground; it is also used figuratively to suggest an abysmal depth, and is sometimes used to mean hell. Excavation is a man-made cavity or pit , as for the foundations of a buildings.