Vernacular

Part of speech: noun (n.)

The vernacular language; one's mother tongue; often, the common forms of expression in a particular locality.

Part of speech: adjective (a.)

Belonging to the country of one's birth; one's own by birth or nature; native; indigenous; -- now used chiefly of language; as, English is our vernacular language. "A vernacular disease." Harvey. His skill the vernacular dialect of the Celtic tongue. Fuller. Which in our vernacular idiom may be thus interpreted. Pope.