The Collaborative International Dictionary of English v.0.48:

Macerate \Mac"er*ate\, v. t. [imp. & p. p. Macerated; p. pr. &
   vb. n. Macerating.] [L. maceratus, p. p. of macerare to
   make soft, weaken, enervate; cf. Gr. ? to knead.]
   1. To make lean; to cause to waste away. [Obs. or R.]
      --Harvey.
      [1913 Webster]

   2. To subdue the appetites of by poor and scanty diet; to
      mortify. --Baker.
      [1913 Webster]

   3. To soften by steeping in a liquid, with or without heat;
      to wear away or separate the parts of by steeping; as, to
      macerate animal or vegetable fiber.
      [1913 Webster]

WordNet (r) 3.0 (2006):

macerate
    v 1: separate into constituents by soaking
    2: become soft or separate and disintegrate as a result of
       excessive soaking; "the tissue macerated in the water"
    3: soften, usually by steeping in liquid, and cause to
       disintegrate as a result; "macerate peaches"; "the gizzards
       macerates the food in the digestive system"
    4: cause to grow thin or weak; "The treatment emaciated him"
       [syn: waste, emaciate, macerate]