The Collaborative International Dictionary of English v.0.48:

Enchain \En*chain"\, v. t. [F. encha[^i]ner; pref. en- (L. in)
   cha[^i]ne chain. See Chain, and cf. Incatenation.]
   1. To bind with a chain; to hold in chains.
      [1913 Webster]

   2. To hold fast; to confine; as, to enchain attention.
      [1913 Webster]

   3. To link together; to connect. --Howell.
      [1913 Webster]

WordNet (r) 3.0 (2006):

enchain
    v 1: restrain or bind with chains