Opus novum
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
In the civil law. A new work. By this term was meant something newly built upon land, or taken from a work already erected. He was said opus novum faeere (to make a new work) who, either by building or by taking anything away, changed the former appearance of a work.
Dig. 39, 1, 1, 11.