Definition of lexicons:
(n) :
The vocabulary of a language.
(n) :
(lexicography, linguistics) A dictionary that includes or focuses on lexemes.
(n) :
The vocabulary used by or known to an individual. (Also called lexical knowledge.)
(n) :
A set of vocabulary specific to a certain subject.
(n) :
A dictionary of Classical Greek, Hebrew, Latin, or Aramaic.
(n) :
A list thereof.