From Citizendium - Reading time: 1 min
Lexicon [r]: Complete set of vocabulary units for a language, including information on their structural specifications (semantic, morphological, syntactic and phonological properties, plus how they inter-relate); also, the mental representation of this lexical knowledge and, in casual usage, a synonym for vocabulary. The word is also common in the titles of dictionaries of Arabic, Aramaic/Syriac, ancient Greek and Hebrew. [e]