adverb (r)

• not easy to believe

  tidak mudah untuk percaya

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

  source: wordnet30
• in an unbelievable manner

  dalam cara yang luar biasa

  Example:
  He was unbelievably angry.
  

  Antonym:
  believably
  

  source: wordnet30