lexicon dictionary
vocabulary – Difference between lexicon and dictionary – English Language & Usage Stack Exchange
What is the difference between a Lexicon and a Dictionary? – Quora
【总结】
lexicon：a list of words that belong to a particular language
Sometimes, lexicon is used as another word for thesaurus
thesaurus：a dictionary of synonyms (different words and phrases that have the same or similar meaning)
dictionary：a list of words and phrases that are (or were) in common usage, together with their definitions
so a dictionary is different from a lexicon because a lexicon is a simple list and doesn’t define the words
vocabulary：a list of words that an individual knows or uses regularly
Vocabulary is different from lexicon because vocabulary is about what an individual or group of people know, whereas lexicon is about the language itself