The Collaborative International Dictionary of English v.0.48:

Potential \Po*ten"tial\, a. [Cf. F. potentiel. See Potency.]
   1. Being potent; endowed with energy adequate to a result;
      efficacious; influential. [Obs.] "And hath in his effect a
      voice potential." --Shak.
      [1913 Webster]

   2. Existing in possibility, not in actuality. "A potential
      hero." --Carlyle.
      [1913 Webster]

            Potential existence means merely that the thing may
            be at ome time; actual existence, that it now is.
                                                  --Sir W.
                                                  Hamilton.
      [1913 Webster]

   Potential cautery. See under Cautery.

   Potential energy. (Mech.) See the Note under Energy.

   Potential mood, or Potential mode (Gram.), that form of
      the verb which is used to express possibility, liberty,
      power, will, obligation, or necessity, by the use of may,
      can, must, might, could, would, or should; as, I may go;
      he can write.
      [1913 Webster]

WordNet (r) 3.0 (2006):

potential energy
    n 1: the mechanical energy that a body has by virtue of its
         position; stored energy [syn: potential energy, P.E.]