The Collaborative International Dictionary of English v.0.48:

Lexicography \Lex`i*cog"ra*phy\
   (l[e^]ks`[i^]*k[o^]g"r[.a]*f[y^]), n. [Cf. F. lexicographie.]
   The art, process, or occupation of making a lexicon or
   dictionary; the principles which are applied in making
   dictionaries; as, with so many words lexicography can be
   interesting in parts but at length is rather tedious labor.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

lexicography
    n 1: the act of writing dictionaries

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "lexicography":
   criticism, cryptanalysis, cryptography, cryptology, diagnostics,
   epigraphy, exegetics, glossography, hermeneutics, lexicology,
   lexigraphy, literary criticism, metoposcopy, oneirology,
   onomasiology, onomastics, onomatology, paleography, pathognomy,
   physiognomics, physiognomy, semantics, semasiology, semeiology,
   semeiotics, symptomatology, textual criticism, tropology