lexis

noun3

1. •
   The set of all words and phrases in a language; any unified subset of words from a particular language.

   • Thus, alongside current lexis, words and senses now obsolete find a place in a dictionary on historical principles. — 2018
2. •
   Words, collocations, and common phrases in a language; vocabulary and word combinations.
3. •
   The vocabulary used by a writer.

   • In this broadsheet newspaper, the reporter uses a complicated and formal lexis which I find hard to understand.