Vulgar Latin

Vulgar Latin - sometimes called Medieval Latin - is the form of Latin spoken, from the final centuries of the Roman Empire to the end of the Middle Ages, throughout the countries of the Mediterranean and in some other areas which had been part of the Roman Empire. Vulgar Latin, which is usually contrasted with Classical Latin, i.e., the language of Cicero, Livy, and Virgil, was a living language and, as such, developed over time as well as differing from one region to another under the influence of, among other things, the various pre-existing native languages of the regions.

Vulgar in the expression Vulgar Latin has no pejorative force, and this use of the word must be distinguished from its (more frequent) use to mean ‘rude, crude, or tasteless’. Vulgar comes from the Latin vulgaris, meaning ‘common’, ‘general’, an adjective from the noun vulgus, ‘the mass of the people’, ‘the public’, ‘the common people’, ‘the crowd’: Vulgar Latin is so called simply because it was a widely spoken form of the language rather than a form used only by the well-educated or the learned.

See also Latin in the History of English