The lexicon is the component of a linguistic system which can be regarded as a list or network of words or lexical entries (also lexical items, lexemes). It contains information about (a) the pronunciation, (b) the meaning, (c) morphological properties, and (d) syntactic properties of its entries. Furthermore, the lexicon must contain at least the idiosyncratic information about its entries.
The term 'lexicon' ambiguous insofar as it is used both for a 'mental lexicon' as the representation of lexical knowledge in a speaker's mind, and as an extensional (e.g. printed, electronic) list of lexical items from a given language.
The relational adjective is lexical.
American structuralists (e.g. Bloomfield 1933)) assume that the lexicon contains only information that is completely idiosyncratic. Any property of a word which can be predicted by phonological, morphological, or syntactic rule will therefore be excluded from the lexicon. In this approach the lexicon is simply a list of morphemes. In other approaches (e.g. Halle (1973), Jackendoff (1975), Aronoff (1976) the lexicon is more complex. Next to a list of underived lexical entries, it contains a word formation component. Hence, in this approach morphology is an integrated part of the lexicon.
The English lexicon contains the adjective opaque and the nominalizing suffix -ity. It furthermore contains a suffixation rule which adds -ity to adjectives, and by means of this rule the form [[opaque] ity] is derived. This form is changed into opacity in the separate phonological component. In a third approach, known as the theory of Lexical Morphology/Phonology (e.g. Kiparsky (1982)), the Lexicon contains (a) a list of underived lexical items, (b) linearly ordered levels of word formation rules, and (c) a list of level ordered phonological rules. The difference between this approach and the preceding one is the position of the (lexical) phonological rules. In the theory of Lexical Morphology/Phonology the derived form [[opaque] ity] is changed into opacity within the Lexicon. These three approaches to the Lexicon are the most prominent ones. Spencer (1991) provides a good review of the function assigned to the Lexicon in a great number of theories. See permanent lexicon and potential lexicon.
- Aronoff, M. 1976. Word Formation in Generative Grammar, MIT-press, Cambridge, Mass.
- Bloomfield 1933. Language, Holt, New York.
- Halle, M. 1973. Prolegomena to a Theory of Word-Formation, Linguistic Inquiry 4, pp. 451-464
- Jackendoff, R. 1975. Morphological and Semantic Regularities in the Lexicon, Language 51, pp. 639-671
- Kiparsky, P. 1982. From Cyclic Phonology to Lexical Phonology, in: Hulst, H. van der and N. Smith (eds.) The Structure of Phonological Representations (I), pp.131-175
- Spencer, A. 1991. Morphological Theory, Blackwell, Oxford.