The Collaborative International Dictionary of English v.0.48:

Gloat \Gloat\, v. i. [imp. & p. p. Gloated; p. pr. & vb. n.
   Gloating.] [Akin to Icel. glotta to smile scornfully, G.
   glotzen to gloat.]
   To look steadfastly; to gaze earnestly; to gaze with
   passionate desire, lust, or avarice.
   [1913 Webster]

   2. To gaze with malignant satisfaction; to exult maliciously,
      sometimes also triumphantly, in another's loss or
      discomfort; -- usually in a bad sense.
      [1913 Webster]

            In vengeance gloating on another's pain. --Byron.
      [1913 Webster]

WordNet (r) 3.0 (2006):

gloat
    n 1: malicious satisfaction [syn: gloat, gloating, glee]
    v 1: dwell on with satisfaction [syn: gloat, triumph,
         crow]
    2: gaze at or think about something with great self-
       satisfaction, gratification, or joy