Black's Law Dictionary (2nd edition)dictionaries

Compound Interest

Interest up-on Interest, i. e., when the Interest of a sum of money is added to the principal, and then bears Interest, which thus becomes a sort of secondary principal. Camp v. Bates, 11 Conn. 487; woods v. Rankin, 2 Heisk. (Tenn.) 46; U. S. Mortg. Co. v. Sperry (C. 0.) 26 Fed. 730

Source: Black's Law Dictionary 2nd Ed (1910)