The Collaborative International Dictionary of English v.0.48:

Nomenclature \No"men*cla`ture\, n. [L. nomenclatura: cf. F.
   nomenclature. See Nomenclator.]
   1. A name. [Obs.] --Bacon.
      [1913 Webster]

   2. A vocabulary, dictionary, or glossary. [R.]
      [1913 Webster]

   3. The technical names used in any particular branch of
      science or art, or by any school or individual; as, the
      nomenclature of botany or of chemistry; the nomenclature
      of Lavoisier and his associates.
      [1913 Webster]

WordNet (r) 3.0 (2006):

nomenclature
    n 1: a system of words used to name things in a particular
         discipline; "legal terminology"; "biological nomenclature";
         "the language of sociology" [syn: terminology,
         nomenclature, language]