- a usually synchronic approach to language study in which a language is analyzed as an independent network of formal systems, each of which is composed of elements that are defined in terms of their contrasts with other elements in the system.
- a school of linguistics that developed in the U.S. during the 1930s–1950s, characterized by such an approach and by an emphasis on the overt formal features of language, especially of phonology, morphology, and syntax.
- a descriptive approach to a synchronic or diachronic analysis of language on the basis of its structure as reflected by irreducible units of phonological, morphological, and semantic features
