Dict: strongs - unbelief
Strongs:
G543 @ ἀπείθεια apeitheia ap-i'-thi-ah From G545; disbelief (obstinate and rebellious): - disobedience unbelief.
G570 @ ἀπιστία apistia ap-is-tee'-ah From G571; faithlessness that is (negatively) disbelief (want of Christian faith) or (positively) unfaithfulness (disobedience): - unbelief.