lexicography \lek-suh-KAH-gruh-fee\ (noun) - 1 : The writing or compiling of dictionaries; the editing or making of dictionaries. 2 : The principles and practices applied to writing dictionaries.
"I am of course stopping short still of the needs of practical lexicography in one conspicuous respect : I am attending only to the cognitive side..." -- W.V. Quine, 'Theories and Things'
Lexicography is derived from the Greek lexicon (biblion), a word- or phrase-book (from lexis, a phrase, a word) + graphein, to write. A lexicographer (thought to be formed on the pattern of geographer) is a compiler or writer of a dictionary -- as defined by Samuel Johnson in his own Dictionary of the English Language, "a writer of dictionaries, a harmless drudge."