The Collaborative International Dictionary of English v.0.48:

Ecstatic \Ec*stat"ic\, n.
   An enthusiast. [R.] --Gauden.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ecstatic \Ec*stat"ic\, a. [Gr. ?, fr. ?: cf. F. extatique. See
   Ecstasy, n.]
   1. Pertaining to, or caused by, ecstasy or excessive emotion;
      of the nature, or in a state, of ecstasy; as, ecstatic
      gaze; ecstatic trance.
      [1913 Webster]

            This ecstatic fit of love and jealousy. --Hammond.
      [1913 Webster]

   2. Delightful beyond measure; rapturous; ravishing; as,
      ecstatic bliss or joy.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ecstatic
    adj 1: feeling great rapture or delight [syn: ecstatic,
           enraptured, rapturous, rapt, rhapsodic]

Moby Thesaurus II by Grady Ward, 1.0:

118 Moby Thesaurus words for "ecstatic":
   abandoned, absent, absentminded, absorbed, abstracted, amok,
   bellowing, bemused, berserk, blissful, bursting with happiness,
   carried away, castle-building, cock-a-hoop, daydreaming, daydreamy,
   delighted, delirious, demoniac, distracted, dreaming, dreamy,
   drowsing, elate, elated, elsewhere, enchanted, engrossed,
   enraptured, enravished, entranced, euphoric, exalted, excited,
   exhilarated, exultant, faraway, feral, ferocious, fierce, flushed,
   flying, frantic, freaked out, frenzied, fulminating, furious, glad,
   gleeful, haggard, half-awake, happy, high, hog-wild, howling,
   hysterical, imparadised, in a reverie, in a transport,
   in ecstasies, in heaven, in hysterics, in paradise, in raptures,
   in seventh heaven, in the clouds, intoxicated, joyful, jubilant,
   lost, lost in thought, mad, madding, maniac, meditative, mooning,
   moonraking, museful, musing, napping, nodding, oblivious,
   on cloud nine, orgasmic, orgiastic, overjoyed, overjoyful, pensive,
   pipe-dreaming, possessed, preoccupied, rabid, raging, ramping,
   ranting, rapt, raptured, rapturous, raving, ravished, rhapsodic,
   roaring, running mad, sent, somewhere else, stargazing, storming,
   taken up, thrilled, transported, unconscious, uncontrollable,
   violent, wild, wild-eyed, wild-looking, woolgathering,
   wrapped in thought