What is Persecutio?

Legal Definition
Lat. In the civil law. A followlug after; a pursuing at law; a suit or prosecution. Properly that kind of judicial proceedlug before the praetor which was called "extraordinary." In a general sense, any judicial proceeding, including not ouiy "actions," (actiones,) properly so called, but other proceedings also. Calvin.
-- Black's Law Dictionary
Legal Definition
(Civil Law) Proceeding against one in a civil or criminal action.
-- Ballentine's Law Dictionary