The Collaborative International Dictionary of English v.0.48:

Lexigraphy \Lex*ig"ra*phy\ (l[e^]ks*[i^]g"r[.a]*f[y^]), n. [Gr.
   le`xis word + -graphy: cf. F. lexigraphie.]
   The art or practice of defining words; definition of words.
   [1913 Webster]