Negationism, denialism of historical facts or accepted interpretation.
A disownment or disavowal
An assertion of untruth.
Refusal to believe that a problem exists.
A defense mechanism involving a refusal to accept the truth of a phenomenon or prospect.
Refusal to admit responsibility for wrongdoing.
A refusal or failure to provide or grant something that is requested or desired.
The negation in logic.
An absence (or rejection) of belief, especially religious belief