unbelieving

US /ˌʌn.bɪˈliː.vɪŋ/
UK /ˌʌn.bɪˈliː.vɪŋ/
1.

inanmayan

not believing that something is true:

:
•
He listened amazed and unbelieving as we told him of this adventure.
:
unbelievably