The Collaborative International Dictionary of English v.0.48:

Spellbound \Spell"bound`\, a.
   Bound by, or as by, a spell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spellbind \Spell"bind`\, v. t. [imp. & p. p. Spellbound; p.
   pr. & vb. n. Spellbinding.]
   To bind or hold by, or as if by, a spell or charm; to
   entrance or fascinate, esp. by eloquence of speech, as in a
   political campaign. -- Spell"bind`er, n.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

spellbound
    adj 1: having your attention fixated as though by a spell [syn:
           fascinated, hypnotized, hypnotised, mesmerized,
           mesmerised, spellbound, spell-bound, transfixed]

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "spellbound":
   agape, aghast, agog, all agog, amazed, arrested, astonished,
   astounded, at gaze, awed, awestruck, becharmed, beguiled,
   bewildered, bewitched, breathless, captivated, castle-building,
   caught, charm-bound, charmed, confounded, daydreaming, daydreamy,
   dreamful, dreaming, dreamlike, dreamy, dreamy-eyed, dreamy-souled,
   dumbfounded, dumbstruck, enchanted, enraptured, enravished,
   enthralled, entranced, fascinated, fixed, flabbergasted, gaping,
   gauping, gazing, gripped, held, hypnotized, in a trance, in awe,
   in awe of, lost in wonder, marveling, mesmerized, open-eyed,
   openmouthed, overwhelmed, pipe-dreaming, popeyed, puzzled, rapt,
   rapt in wonder, spell-caught, spelled, staggered, staring,
   stupefied, surprised, thunderstruck, tranced, under a charm,
   under a spell, wide-eyed, wonder-struck, wondering