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):

spellbinding
    adj 1: attracting and holding interest as if by a spell; "read
           the bedtime story in a hypnotic voice"; "she had a warm
           mesmeric charm"; "the sheer force of his presence was
           mesmerizing"; "a spellbinding description of life in
           ancient Rome" [syn: hypnotic, mesmeric,
           mesmerizing, spellbinding]