unbelievable

/ˌʌnbɪˈliːvəbəl/
adjective
  1. Extremely surprising or hard to believe; amazing.
    • It's unbelievable how much she has improved in just one month.
    • The magician performed an unbelievable trick that left the audience speechless.
    • They won the game in the final seconds — it was unbelievable!
  2. So unlikely or improbable that it is difficult to accept as true.
    • The plot of the movie was so unbelievable that nobody enjoyed it.
    • His story about being a spy was completely unbelievable.
    • The excuse she gave for being late was simply unbelievable.