1 (also the lexicon) [sing.] (linguistics) all the words and phrases used in a particular language or subject; all the words and phrases used and known by a particular person or group of people:
the lexicon of finance and economics
2 [C] a list of words on a particular subject or in a language in alphabetical order:
a lexicon of technical scientific terms
3 [C] a dictionary, especially one of an ancient language, such as Greek or Hebrew
