3. (Math.) One of the ten figures or symbols, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, by which all numbers are expressed; -- so called because of the use of the fingers in counting and computing.
By some authorities the symbol 0 is not included with the digits.
4. (Anat.) One twelfth part of the diameter of the sun or moon; -- a term used to express the quantity of an eclipse; as, an eclipse of eight digits is one which hides two thirds of the diameter of the disk.