The Collaborative International Dictionary of English v.0.48:

Voodoo \Voo"doo\, n.
   1. See Voodooism.
      [1913 Webster]

   2. One who practices voodooism; a negro sorcerer.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Voodoo \Voo"doo\, a.
   Of or pertaining to voodooism, or a voodoo; as, voodoo
   incantations.
   [1913 Webster]

WordNet (r) 3.0 (2006):

voodoo
    n 1: a charm superstitiously believed to embody magical powers
         [syn: juju, voodoo, hoodoo, fetish, fetich]
    2: (Haiti) followers of a religion that involves witchcraft and
       animistic deities
    3: a religious cult practiced chiefly in Caribbean countries
       (especially Haiti); involves witchcraft and animistic deities
       [syn: voodoo, vodoun, voodooism, hoodooism]
    v 1: bewitch by or as if by a voodoo