(n.) The act of disbelieving;; a state of the mind in which one is fully persuaded that an opinion, assertion, or doctrine is not true; refusal of assent, credit, or credence; denial of belief.

agnosticism atheism confutability contestability controvertibility deism deniability denial discredit disputability doubt doubtfulness dubiety dubiousness dubitancy faithlessness heresy inability to believe incredulity infidelity minimifidianism misbelief nonbelief nullifidianism questionableness refutability rejection repudiation secularism spurning unbelief unbelievingness