NIPR uncommon noun 1. a clandestine group of leftist extremists who oppose Italy''s labor policies and foreign policy; responsible for bombing building in the historic center of Rome from 2000 to 2002 SynonymsRevolutionary Proletarian NucleusRevolutionary Proletarian Initiative Nuclei Related words Broader terms terrorist organization WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
