Noun
propraetor (plural propraetors)
A magistrate of ancient Rome who governed a province after serving as a praetor in Rome.
After a term as Praetor, the magistrate would serve as a provincial governor in the office of Propraetor, wielding Propraetor imperium, commanding the province’s legions, and possessing ultimate authority within his province(s). Source: Internet
Republican governors were all men who had served in senior magistracies (the consulate or praetorship ) in Rome in the previous year, and carried related titles as governor (proconsul or propraetor). Source: Internet
In addition, Octavian was granted propraetor imperium (commanding power) which legalized his command of troops, sending him to relieve the siege along with Hirtius and Pansa (the consuls for 43 BC). Source: Internet