Vocabulary
Part of speech: noun
Definition: A usually alphabetized and explained collection of words e.g. of a particular field, or prepared for a specific purpose, often for learning. The collection of words a person knows and uses. The stock of words used in a particular field. The words of a language collectively.
Example sentence: They say, 'Nothing can be done here!' I reply, 'I know no such word in the vocabulary I adopt!'
Lexicon
Part of speech: noun
Definition: A dictionary that includes or focuses on lexemes.A dictionary of Classical Greek, Hebrew, Latin, or Aramaic.The lexicology of a programming language. (Usually called lexical structure.)Any dictionary.The vocabulary used by or known to an individual. (Also called lexical knowledge)