unbelieve
/ˌʌnbɪˈliːvəbəl/Definitions
1. adjective
so surprising or impressive as to be difficult to believe
“The magician’s trick was truly unbelievable.”
2. adjective
not able to believe something
“I find it unbelievable that he wouldn’t help someone in need.”
3. verb
to refuse to believe something
“She refused to believe the news of her friend’s passing.”