the vocabulary of a language, as distinct from its grammar; the total stock of words and idiomatic combinations of them in a language; lexicon.
Origin
1955-60; < Greekléxis speech, diction, word, text, equivalent to lég(ein) to speak, recount (akin to lógos account, word, Latinlegere to read; see logos, lection) + -sis-sis
British Dictionary definitions for lexis
lexis
/ˈlɛksɪs/
noun
1.
the totality of vocabulary items in a language, including all forms having lexical meaning or grammatical function