The language of a people or a national language.

“A vernacular of the United States is English.”

Everyday speech or dialect, including colloquialisms, as opposed to standard, literary, liturgical, or scientific idiom.

“Street vernacular can be quite different from what is heard elsewhere.”

Language unique to a particular group of people; jargon, argot.

“For those of a certain age, hiphop vernacular might just as well be a foreign language.”

Of or pertaining to everyday language, as opposed to standard, literary, liturgical, or scientific idiom.

Belonging to the country of one's birth; one's own by birth or nature; native; indigenous.

“a vernacular disease”

Of or related to local building materials and styles; not imported.