A regional dialect is a variety of language spoken in a particular geographical area. PATOIS and IDIOM are two terms used to describe regional dialects. PATOIS is a term used to refer to a regional dialect that has its own vocabulary, grammar, and pronunciation. IDIOM is a term used to refer to a regional dialect that has its own set of expressions and phrases. Both PATOIS and IDIOM are used to refer to regional dialects that are distinct from the standard language of the region.