Black's Law Dictionary (2nd edition)dictionaries

Simul Cum

Lat Together with. In actions of tort and in prosecutions, where several persons united in committing the act complained of, some of whom are known and others not, it is usual to allege in the dec-laration or indictment that the persons therein named did the injury in question, “together with (simnl cum) other persons unknown.”

Source: Black's Law Dictionary 2nd Ed (1910)