Con″stant, n. 1. That which is not subject to change; that which is invariable.
2. (Math.) A quantity that does not change its value; — used in countradistinction to variable.
Absolute constant(Math.), one whose value is absolutely the same under all circumstances, as the number 10, or any numeral. — Arbitrary constant, an undetermined constant in a differential equation having the same value during all changes in the values of the variables.