Synonyms for Vernacular (same or very similar meaning)
WordNet sense 1 (a characteristic language of a particular group (as among thieves)):
argot, cant, jargon, lingo, patois, slang, jargonWordNet sense 2 (being or characteristic of or appropriate to everyday language):
common, vulgarWordNet sense 3 (used of spoken and written language):
informalFrom the ODE community, based on WordNetadd/edit