A referendum (: referendums or referenda) is a direct vote by the electorate on a proposal, law, or political issue. This is in contrast to an issue being voted on by a representative. This may result in the adoption of a new policy or specific law, or the referendum may be only advisory. In some countries, it is synonymous with and also known as plebiscite, votation, popular consultation, ballot question, ballot measure, or proposition.
Some definitions of 'plebiscite' suggest it is a type of vote to change the constitution or government of a country. The word, 'referendum' is often a catchall, used for both legislative referrals and initiatives.
'Referendum' is the gerundive form of the Latin verb referre, literally "to carry back" (from the verb ferre, "to bear, bring, carry" plus the inseparable prefix re-, here meaning "back"). As a gerundive is an adjective, not a noun, it cannot be used alone in Latin, and must be contained within a context attached to a noun such as Propositum quod referendum est populo, "A proposal which must be carried back to the people". The addition of the verb sum (3rd person singular, est) to a gerundive, denotes the idea of necessity or compulsion, that which "must" be done, rather than that which is "fit for" doing. Its use as a noun in English is not considered a strictly grammatical usage of a foreign word but is rather a freshly coined English noun, which follows English grammatical usage, not Latin grammatical usage. This determines the form of the plural in English, which according to English grammar should be "referendums". The use of "referenda" as a plural form in English (treating it as a Latin word and attempting to apply to it the rules of Latin grammar) is unsupportable according to the rules of both Latin and English grammar. The use of "referenda" as a plural form is posited hypothetically as either a gerund or a gerundive by the Oxford English Dictionary, which rules out such usage in both cases as follows:
Referendums is logically preferable as a plural form meaning 'ballots on one issue' (as a Latin gerund, referendum has no plural).