A cover-up is an attempt, whether successful or not, to conceal evidence of wrongdoing, error, incompetence, or other embarrassing information. Research has distinguished personal cover-ups from relational cover-ups.
"An ostrich only thinks he 'covers up'."
The Ottoman government attempted to ban foreigners from taking photographs such as this one of Armenian genocide victims in an effort to cover up the genocide.
Front page of the newspaper L’Aurore of Thursday 13 January 1898, with the famous open letter J'Accuse…! written by Émile Zola to the President of France about the Dreyfus Affair. The headline reads "I accuse! Letter to the President of the Republic". See J'accuse...!, the whole text on Wikisource
Denial, in ordinary English usage, has at least three meanings: asserting that any particular statement or allegation is not true ; the refusal of a request; and asserting that a true statement is not true.
A 17th century painting depicting the Denial of Peter, a story told in the four Gospels in the New Testament. In it, Peter denies having associated with Jesus, who is being sought by authorities.