vernacular
noun
he wrote in the vernacular and adopted a nonacademic style accessible to the public:
everyday language, spoken language, colloquial speech, native speech, conversational language, common parlance, nonstandard language, jargon, -speak, cant, slang, idiom, argot, patois, dialect;
regional language, local tongue, regionalism, localism, provincialism;
informal lingo, local lingo, patter, geekspeak;
rare idiolect.
▷antonyms formal language; Latin.