lexemeA fundamental unit of the vocabulary of a language.
lexical databaseA database containing terms as well as information about the terms such as part of speech, type of term, etc.
lexicographerA person who is knowledgeable about terms, their uses, parts of speech, etc. Lexicographers often construct controlled vocabularies.
literary warrantJustification for the representation of a concept in an indexing language or for the selection of a preferred term because of its frequent occurrence in the literature. See also organizational warrant and user warrant.