The Collaborative International Dictionary of English v.0.48:

Adopt \A*dopt"\, v. t. [imp. & p. p. Adopted; p. pr. & vb. n.
   Adopting.] [L. adoptare; ad + optare to choose, desire: cf.
   F. adopter. See Option.]
   1. To take by choice into relationship, as, child, heir,
      friend, citizen, etc.; esp. to take voluntarily (a child
      of other parents) to be in the place of, or as, one's own
      child.
      [1913 Webster]

   2. To take or receive as one's own what is not so naturally;
      to select and take or approve; as, to adopt the view or
      policy of another; these resolutions were adopted.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "adopt":
   Americanize, Anglicize, accept, acculturate, acculturize, admit,
   affect, affiliate, appropriate, approve, arrogate, assimilate,
   assume, carry, colonize, confer citizenship, conquer, copy,
   derive from, domesticate, embrace, encroach, enslave, espouse,
   go in for, go native, hog, imitate, indent, infringe, invade,
   jump a claim, make free with, make use of, mock, monopolize,
   naturalize, occupy, overrun, pass, pirate, plagiarize, play God,
   preempt, preoccupy, prepossess, pretend to, ratify, requisition,
   seize, simulate, sit on, squat on, steal, subjugate, take,
   take all of, take in, take it all, take on, take over,
   take possession of, take up, trespass, usurp