Definition of Edictum
In the Roman law, an edict; a mandate, or ordinance. An ordinance, or law, enacted by the emperor without the senate; belonging to the class of constitutiones principis. An edict was a mere voluntary constitution of the emperor; differing from a rescript, in not being returned in the way of answer; and from a decree, in not being given in judgment; and from both, in not being founded upon solicitation.
A general order published by the praetor, on entering upon his office, containing the system of rules by which he would administer justice during the year of his office.
That's the definition of Edictum in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.