The Collaborative International Dictionary of English v.0.48:

emasculation \e*mas`cu*la"tion\, n.
   1. The act of depriving of virility, or the state of being so
      deprived; castration.
      [1913 Webster]

   2. The act of depriving, or state of being deprived, of vigor
      or strength; unmanly weakness.
      [1913 Webster]

WordNet (r) 3.0 (2006):

emasculation
    n 1: loss of power and masculinity
    2: neutering a male animal by removing the testicles [syn:
       castration, emasculation]