The Collaborative International Dictionary of English v.0.48:

Inthrall \In*thrall"\, v. t. [imp. & p. p. Inthralled; p. pr.
   & vb. n. Inthralling.] [Cf. Enthrall.] [Written also
   inthral, enthral, and enthrall.]
   To reduce to bondage or servitude; to make a thrall, slave,
   vassal, or captive of; to enslave.
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         She soothes, but never can inthrall my mind. --Prior.
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