sua sponte

A borrowing of Latin sua sponte (“at its own prompting; by its own impulse; of its own free will”)

sua sponte

1. (law) Without prompting or suggestion; on its own initiative.
   • 1878, "Decretals" in the Encyclopædia Britannica, 9th ed., Vol. VII, p. 22:

     Decretals... ought, properly speaking, to be distinguished, on the one hand from constitutions... enacted by the Pope sua sponte without reference to any particular case, and on the other hand from rescripts... which apply only to special circumstances or individuals, and constitute no general precedent. But this nomenclature is not strictly observed.

• Usually used when the court issues an order or otherwise acts without being petitioned to do so.

• suo motu, nostra sponte, motu proprio

• off one's own bat

• Black's Law Dictionary 10th Edition (2014)