1. （某一学科、个人或群体的）全部词汇
The lexicon of a particular subject is all the terms associated with it. The lexicon of a person or group is all the words they commonly use.

2. （某一语言或学科的）词汇表
A lexicon is an alphabetical list of the words in a language or the words associated with a particular subject.

3. （尤指希腊语、希伯来语等古老语言的）词典，字典
A lexicon is a dictionary, especially of a very old language such as Greek or Hebrew.

1. a language user's knowledge of words

Synonym: vocabularymental lexicon

2. a reference book containing an alphabetical list of words with information about them

Synonym: dictionary