Non pros., abbrev. For non prosequitur (he [the plaintiff] does not pursue [his action]). Where the plaintiff failed to take the proper step in his action in the proper time, the defendant entered what was called a non prosequitur, and signed final judgment against the plaintiff, who was said to be non pros.
Under R.S.C. 1883, Ord. XXVII., when the plaintiff neglects to proceed, the course is for the defendant to apply for a dismissal of the action for want of prosecution.