The Collaborative International Dictionary of English v.0.48:

Vocabulary \Vo*cab"u*la*ry\ (v[-o]*k[a^]b"[-u]*l[asl]*r[y^]),
   n.; pl. Vocabularies. [LL. vocabularium, vocabularius: cf.
   F. vocabulaire. See Vocable.]
   1. A list or collection of words arranged in alphabetical
      order and explained; a dictionary or lexicon, either of a
      whole language, a single work or author, a branch of
      science, or the like; a word-book.
      [1913 Webster]

   Note: The "vocabulary" of this dictionary referred to within
         the definitions of certain collocations are those words
         serving as headwords for main entries, and
         distinguished from word combinations ("collocations")
         which follow the main part of certain entries. In the
         XML-tagged version, these headwords are marked by the
         tags

WordNet (r) 3.0 (2006):

vocabulary
    n 1: a listing of the words used in some enterprise
    2: a language user's knowledge of words [syn: vocabulary,
       lexicon, mental lexicon]
    3: the system of techniques or symbols serving as a means of
       expression (as in arts or crafts); "he introduced a wide
       vocabulary of techniques"

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "vocabulary":
   argot, biographical dictionary, cant, chemical dictionary,
   desk dictionary, dialect dictionary, dictionary,
   dictionary of quotations, electronics dictionary,
   etymological dictionary, foreign-language dictionary, gazetteer,
   general dictionary, geological dictionary, gibberish, gloss,
   glossary, gobbledygook, gradus, jargon, language, lexicon, lexis,
   lingo, mumbo jumbo, nomenclator, onomasticon, palaver, patois,
   patter, phrase book, phraseology, polyglot dictionary, promptorium,
   rhyming dictionary, scatology, science dictionary, slang,
   slang dictionary, specialized dictionary, stock of words,
   synonym dictionary, synonymy, taboo language, terminology,
   thesaurus, treasury of words, unabridged dictionary, verbal,
   verbiage, vernacular, vocabular, vulgar language, word list,
   wordage, wordbook, wordhoard, words