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.
Negationism, denialism of historical facts or accepted interpretation.
The negation in logic.
The act of one who undertakes (in either sense).
A promise or pledge; a guarantee.
That which is undertaken; any business, work, or project which a person engages in, or attempts to perform; an enterprise.
The business of an undertaker, or the management of funerals.