lexica

Lexicon is the set of words and fixed expressions in a language or domain, together with information about their meanings, pronunciations, and grammatical properties. More loosely, it can refer to the vocabulary of a person or field. The plural forms are lexica (a Latin plural) and lexicons, with lexica favored in academic writing when discussing multiple word lists or dictionaries.

Lexicography is the discipline of compiling and editing dictionaries, and a lexicon entry typically includes the lemma (canonical form), one or more senses, part of speech, pronunciation, inflectional information, etymology, usage notes, and sometimes example sentences. Lexica may be general, aiming to cover a language as a whole, or domain-specific, such as medical, legal, or technical lexica. They also address multiword expressions and semantic relations like synonyms, antonyms, and collocations.

In linguistics, the mental lexicon refers to the internal store of knowledge about words—their forms and meanings and how they are used in speech. Externally, lexica comprise printed and digital dictionaries, word lists, and lexical databases used in research and education.

In computational linguistics and natural language processing, lexica serve as resources for analysis and generation. They include sentiment lexica, bilingual or multilingual lexica, and lexical databases such as WordNet. Lexica support tasks such as tokenization, part-of-speech tagging, parsing, information retrieval, and machine translation, and may be derived from corpora or curated by experts.