n. A declaration; proclamation.n. A fiscal period of fifteen years, established by Constantine the Great after the reorganization of the Roman Empire, being the term during which the annual tax on real property was paid on the basis of a valuation made and proclaimed at the beginning of each quindecennial period. This became a common and convenient means for dating ordinary transactions.n. Hence In chronology, a year bearing a number, or the number attached to the year, showing its place in a cycle of fifteen years, counting from a. d. 313.