The Collaborative International Dictionary of English v.0.48:

Adopted \A*dopt"ed\, a.
   Taken by adoption; taken up as one's own; as, an adopted son,
   citizen, country, word. -- A*dopt"ed*ly, adv.
   [1913 Webster]

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]

WordNet (r) 3.0 (2006):

adopted
    adj 1: acquired as your own by free choice; "my adopted state";
           "an adoptive country" [syn: adopted, adoptive] [ant:
           native]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "adopted":
   Americanized, Anglicized, accepted, acculturated, acculturized,
   appointed, approved, assimilated, carried, chosen, designated,
   elect, elected, elected by acclamation, embraced, espoused,
   handpicked, indoctrinated, named, naturalized, nominated, passed,
   picked, ratified, select, selected, unanimously elected