Lexicon (noun)

1. A vocabulary of a particular language, person, or group of people.
2. A collection of words and their meanings in a particular language.

Origin:

From late latin 'lexicon' meaning 'a dictionary'.

Examples:

1. The lexicon of the language was diverse and complex, reflecting its history and culture.
2. The lexicon of the author was rich and imaginative, reflecting his education and experience.
3. The lexicon of the slang was colorful and informal, reflecting the youth and their subculture.
4. The lexicon of the scientific paper was technical and precise, reflecting the research and findings.
5. The lexicon of the poetry was musical and metaphorical, reflecting the artist and his vision.