Dialect
One usage--the more common among linguists--refers to a variety of a language that is a characteristic of a particular group of the language's speakers. The term is applied most often to regional speech patterns, but a dialect may also be defined by other factors, such as social class. A dialect that is associated with a particular social class can be termed a sociolect, a dialect that is associated with a particular ethnic group can be termed as ethnolect, and a regional dialect may be termed a regiolect. According to this definition, any variety of a language constitutes "a dialect", including any standard varieties.
What is the term dialect most often applied to?
regional speech patterns
The term is applied most often to regional speech patterns, but a dialect may also be defined by other factors, such as social class.
Dialect