The Collaborative International Dictionary of English v.0.48:

Rapacious \Ra*pa"cious\ (r[.a]*p[=a]"sh[u^]s), a. [L. rapax,
   -acis, from rapere to seize and carry off, to snatch away.
   See Rapid.]
   [1913 Webster]
   1. Given to plunder; disposed or accustomed to seize by
      violence; seizing by force. " The downfall of the
      rapacious and licentious Knights Templar." --Motley.
      [1913 Webster]

   2. Accustomed to seize food; subsisting on prey, or animals
      seized by violence; as, a tiger is a rapacious animal; a
      rapacious bird.
      [1913 Webster]

   3. Avaricious; grasping; extortionate; also, greedy;
      ravenous; voracious; as, rapacious usurers; a rapacious
      appetite.
      [1913 Webster]

            [Thy Lord] redeem thee quite from Death's rapacious
            claim                                 --Milton.
      [1913 Webster]

   Syn: Greedy; grasping; ravenous; voracious.
        [1913 Webster] -- Ra*pa"cious*ly, adv. --
        Ra*pa"cious*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

rapaciousness
    n 1: extreme gluttony [syn: edacity, esurience,
         rapaciousness, rapacity, voracity, voraciousness]
    2: an excessive desire for wealth (usually in large amounts);
       "the greediness of lawyers" [syn: greediness,
       voraciousness, rapaciousness]