“Vernacular: (Latin vernaculus “domestic, native, indigenous’) Domestic or native language. Now applied to the language used in one’s native country. It may also be used to distinguish between a ‘literary’ language and a dialect; for instance, William Barnes’s ‘vernacular poems,’ and outstanding example of dialect (q.v.) poetry.”
Excerpted from: Cuddon, J.A. The Penguin Dictionary of Literary Terms and Literary Theory. New York: Penguin, 1992.