Lexicon is also a synonym for dictionary or encyclopedic dictionary. For other uses, see lexicon . In linguistics, the lexicon of a language is its vocabulary, including its words and expressions. More formally, it is a language's inventory of lexemes. The lexicon includes the lexemes used to actualize words. Lexemes are formed according to morpho-syntactic rules and express sememes. In this sense, a lexicon organizes the mental vocabulary in a speaker's mind: First, it organizes the vocabulary of a language according to certain principles (for instance, all verbs of motion may be linked in a lexical network) and second, it contains a generative device producing (new) simple and complex words according to certain lexical rules. For example, the suffix '-able' can be added to transitive verbs only, so that we get 'read-able' but not '*cry-able'. Usually a lexicon is a container for words belong