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