In linguistics

Linguistics

Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....

, an idiolect is a variety

Variety (linguistics)

In sociolinguistics a variety, also called a lect, is a specific form of a language or language cluster. This may include languages, dialects, accents, registers, styles or other sociolinguistic variation, as well as the standard variety itself...

 of a language

Language

Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...

 unique to an individual. It is manifested by patterns of vocabulary

Vocabulary

A person's vocabulary is the set of words within a language that are familiar to that person. A vocabulary usually develops with age, and serves as a useful and fundamental tool for communication and acquiring knowledge...

 or idiom

Idiom

Idiom is an expression, word, or phrase that has a figurative meaning that is comprehended in regard to a common use of that expression that is separate from the literal meaning or definition of the words of which it is made...

 selection (the individual's lexicon

Lexicon

In linguistics, the lexicon of a language is its vocabulary, including its words and expressions. A lexicon is also a synonym of the word thesaurus. More formally, it is a language's inventory of lexemes. Coined in English 1603, the word "lexicon" derives from the Greek "λεξικόν" , neut...

), grammar

Grammar

In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...

, or pronunciation

Pronunciation

Pronunciation refers to the way a word or a language is spoken, or the manner in which someone utters a word. If one is said to have "correct pronunciation", then it refers to both within a particular dialect....

s that are unique to the individual. Every individual's language production

Language production

In psycholinguistics, language production is the production of spoken or written language. It describes all of the stages between having a concept, and translating that concept into linguistic form...

 is in some sense unique. Linguists disagree about exactly what is shared, in terms of the underlying knowledge of the language, among speakers of the same language or dialect

Dialect

The term dialect is used in two distinct ways, even by linguists. One usage 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,...

.
The notion of a language is used as an abstract description of the language use and abilities of individual speakers and listeners.