adjective (a)

• of parents and children; related by adoption(adj.all)

  Example:
  Adoptive parents.
  

  Antonym:
  biological
  

  source: wordnet30
• acquired as your own by free choice(adj.all)

  Example:
  An adoptive country.
  

  Synonym:
  adopted
  Antonym:
  native
  

  source: wordnet30
• Pertaining to adoption; made or acquired by adoption; fitted to adopt; as, an adoptive father, an child; an adoptive language.(adjective)

  source: webster1913