The term dialect (from the ancient Greek word διάλεκτος diálektos, "discourse", from διά diá, "through" and λέγω legō, "I speak") is used in two distinct ways. 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 or topolect. According to this definition, any variety of a language constitutes "a dialect", including any standard varieties.The other usage refers to a language that is socially subordinated to a regional or national standard language, often historically cognate to the standard, but not derived from it. In this sense, the standard language is not itself considered a dialect.A dialect is distinguished by its vocabulary, grammar, and pronunciation (phonology, including prosody). Where a distinction can be made only in terms of pronunciation (including prosody, or just prosody itself), the term accent may be preferred over dialect. Other types of speech varieties include jargons, which are characterized by differences in lexicon (vocabulary); slang; patois; pidgins; and argots.The particular speech patterns used by an individual are termed an idiolect.