Vulgar Latin

Vulgar Latin is any of the "nonstandard" (as opposed to "classical") forms of Latin from which the Romance languages developed. The word "Vulgar" in this usage comes from the Latin for "common," as Vulgar Latin was the spoken language, and not from the English word meaning crude or objectionable. Works written in Latin during classical times used Classical Latin rather than Vulgar Latin (originally called sermo vulgaris), with very few exceptions (most notably sections of Gaius Petronius' Satyricon). Because of its nonstandard nature, vulgar Latin had no official orthography. Vulgar Latin is sometimes also called colloquial Latin, or Common Romance (particularly in the late stage). In Renaissance Latin, vulgar Latin was called vulgare Latinum or Latinum vulgare.

The broad term Vulgar Latin should not be confused with the more specific term Proto-Romance, which refers specifically to the theoretical common ancestor to the modern Romance languages. As such Proto-Romance may have been only one of the Vulgar Latin languages and only a very late stage of that language branch.