The Collaborative International Dictionary of English v.0.48:

Omnipotent \Om*nip"o*tent\, a. [F., fr.L. omnipotens, -entis;
   omnis all + potens powerful, potent. See Potent.]
   1. Able in every respect and for every work; unlimited in
      ability; all-powerful; almighty; as, the Being that can
      create worlds must be omnipotent.
      [1913 Webster]

            God's will and pleasure and his omnipotent power.
                                                  --Sir T. More.
      [1913 Webster]

   2. Having unlimited power of a particular kind; as,
      omnipotent love. --Shak.
      [1913 Webster]

   The Omnipotent, The Almighty; God. --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

omnipotent
    adj 1: having unlimited power [syn: almighty, all-powerful,
           omnipotent]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "omnipotent":
   absolute, all-knowing, all-powerful, all-seeing, all-wise,
   almighty, boundless, changeless, creating, creative, divine,
   eternal, eternally the same, everlasting, glorious, godlike, good,
   hallowed, highest, holy, immortal, immutable, infinite, just,
   limitless, loving, luminous, majestic, making, merciful, numinous,
   omnipresent, omniscient, one, permanent, perpetual,
   plenipotentiary, radiant, sacred, shaping, sovereign, supreme,
   timeless, ubiquitous, unbounded, unchanging, undefined, unlimited,
   unrestricted