IPA: /ˌlɛksɪˈkɒɡrəfi/
KK: /lɛksɪˈkɒɡrəfi/
The activity of creating, editing, or compiling dictionaries.
She studied lexicography to learn how dictionaries are made.
Lexicography → It is formed from "lexis" (from Greek, meaning word or speech) and "graphia" (from Greek, meaning writing). The word refers to the writing or compiling of words, specifically in dictionaries.
Think of 'words' ('lexis') being 'written' ('graphia') down — that's what lexicography means.