The Collaborative International Dictionary of English v.0.48:

Empower \Em*pow"er\, v. t. [imp. & p. p. Empowered; p. pr. &
   vb. n. Empowering.]
   1. To give authority to; to delegate power to; to commission;
      to authorize (having commonly a legal force); as, the
      Supreme Court is empowered to try and decide cases, civil
      or criminal; the attorney is empowered to sign an
      acquittance, and discharge the debtor.
      [1913 Webster]

   2. To give moral or physical power, faculties, or abilities
      to. "These eyes . . . empowered to gaze." --Keble.
      [1913 Webster]

   3. to enable or permit; to give more opportunity for
      independent action.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

empowered \empowered\ adj.
   1. invested with legal power or official authority especially
      as symbolized by having a scepter.

   Syn: sceptered, sceptred.
        [WordNet 1.5]

   2. enabled or permitted; as, the women's liberation movement
      empowered wives to take more control of their own lives.
      [PJC]

WordNet (r) 3.0 (2006):

empowered
    adj 1: invested with legal power or official authority
           especially as symbolized by having a scepter [syn:
           empowered, sceptered, sceptred]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "empowered":
   absolute, ascendant, authoritarian, authoritative, authorized,
   autocratic, chartered, clothed with authority, commanding,
   competent, consequential, considerable, controlling, dominant,
   duly constituted, eminent, enfranchised, entitled, ex officio,
   franchised, governing, great, hegemonic, hegemonistic, imperative,
   important, influential, leading, licensed, mighty, momentous,
   monocratic, official, patented, potent, powerful, preeminent,
   prestigious, privileged, prominent, puissant, ranking, ruling,
   sanctioned, senior, substantial, superior, supreme, totalitarian,
   warranted, weighty