adverb (r)

• not easy to believe(adv.all)

  Example:
  Behind you the coastal hills plunge to the incredibly blue sea backed by the Turkish mountains.
  

  Synonym:
  implausibly, improbably, unbelievably
  Antonym:
  believably, credibly, plausibly, probably
  

  source: wordnet30
• exceedingly; extremely(adv.all)

  source: wordnet30
• In an incredible manner.(adverb)

  source: webster1913