The Collaborative International Dictionary of English v.0.48:

emasculate \e*mas"cu*late\, a.
   Deprived of virility or vigor; unmanned; weak. "Emasculate
   slave." --Hammond.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Emasculate \E*mas"cu*late\, v. t. [imp. & p. p. Emasculated;
   p. pr. & vb. n. Emasculating.] [L. emasculare; e + masculus
   male, masculine. See Male masculine.]
   1. To deprive of virile or procreative power; to castrate
      power; to castrate; to geld.
      [1913 Webster]

   2. To deprive of masculine vigor or spirit; to weaken; to
      render effeminate; to vitiate by unmanly softness.
      [1913 Webster]

            Luxury had not emasculated their minds. --V. Knox.
      [1913 Webster]

WordNet (r) 3.0 (2006):

emasculate
    adj 1: having unsuitable feminine qualities [syn: effeminate,
           emasculate, epicene, cissy, sissified,
           sissyish, sissy]
    v 1: deprive of strength or vigor; "The Senate emasculated the
         law" [syn: emasculate, castrate]
    2: remove the testicles of a male animal [syn: emasculate,
       castrate, demasculinize, demasculinise]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "emasculate":
   alter, castrate, cripple, debilitate, demasculinize, desex,
   desexualize, devitalize, disable, effeminate, effeminatize,
   effeminize, enervate, etiolate, eunuchize, exhaust, fix, forceless,
   geld, hamstring, hobble, impotent, inadequate, incapacitate,
   ineffective, ineffectual, lame, maim, sissify, soften, spay,
   spineless, sterilize, unman, unnerve, unsex, unstring, wan, weak,
   wing, womanize