Source : Webster's Revised Unabridged Dictionary (1913)

Almighty \Al*might"y\ ([add]l*m[imac]t"[y^]), a. [AS. ealmihtig,
   [ae]lmihtig; eal (OE. al) all + mihtig mighty.]
   1. Unlimited in might; omnipotent; all-powerful;
      irresistible.

            I am the Almighty God.                --Gen. xvii.
                                                  1.

   2. Great; extreme; terrible. [Slang]

            Poor Aroar can not live, and can not die, -- so that
            he is in an almighty fix.             --De Quincey.

   {The Almighty}, the omnipotent God. --Rev. i. 8.

Source : WordNet®

almighty
     adj : having unlimited power [syn: {all-powerful}, {omnipotent}]
     n : terms referring to the Judeo-Christian God [syn: {Godhead},
         {Lord}, {Creator}, {Maker}, {Divine}, {God Almighty}, {Jehovah}]