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.

Unfaithfulness by virtue of being unreliable or treacherous; SYN. falseness, fickleness, inconstancy.

ETYM Pref. un- not + belief: cf. as. ungeleáfa.
A rejection of belief; SYN. disbelief.