adverb (r)

• in an unnatural way(adv.all)

  Example:
  His other arm lay across his chest, unnaturally, as if placed there deliberately, for a purpose.
  

  source: wordnet30
• not according to nature; not by natural means(adv.all)

  Synonym:
  artificially, by artificial means
  Antonym:
  naturally
  

  source: wordnet30
• in a manner at variance with what is natural or normal(adv.all)

  Example:
  The early Church not unnaturally adopted the position that failure to see the messianic character of his work was really caused by the people's own blindness.
  

  Antonym:
  course, naturally, of course
  

  source: wordnet30