noun

• (law, politics) A direct popular vote on an issue of public importance, such as an amendment to the constitution, a change in the sovereignty of the nation, or some government policy.
• (by extension) An expression of the public's views on an issue, whether legally binding or not.
• (Ancient Rome, historical) Synonym of plebiscitum (“a law enacted by the common people, under the superintendence of a tribune or some subordinate plebeian magistrate, without the intervention of the senate”)