Black's Law Dictionary (2nd edition)dictionaries

Non Liquet

Lat It is not clear. In the Roman courts, when any of the judges, after the hearing of a cause, were not satis-fled that tiie case was made clear enough for them to pronounce a verdict, they were privileged to signify this opinion by casting a ballot inscribed wlth the letters “N. L.,” the abbreviated form of the phrase “non liquet

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