A cover-up is an attempt, whether successful or not, to conceal evidence of wrongdoing, error, incompetence, or other embarrassing or criminalizing information. Research has distinguished personal cover-ups (covering up one's own misdeeds) from relational cover-ups (covering up someone else's misdeeds)
The expression is usually applied to people in positions of authority who abuse power to avoid or silence criticism or to deflect guilt of wrongdoing.
A cover-up is an attempt, successful or not, to conceal or prevent discovery of information or evidence about a crime, mistake, or unethical actions, often to safeguard reputation. It differs from other unethical behavior as a reaction to earlier questionable behavior.
There are different types of coverup organized by the scale and motive for the cover-up. Personal cover-ups are intended to hide an individual's actions and relational cover-ups occur when someone attempts to conceal another person's actions. There are also institutional or organizational cover-ups where a group is involved, and multiagency where multiple institutions take part in a cover-up. Psychology professor Anthony Montgomery writes that there are "elements that are crucial for the development and maintenance of [organizational] cover-ups: (1) Unwilling, but compliant, participants who are unlikely to be whistleblowers, (2) Suppressing/withholding important information, (3) Proactively engaging the support of related actors/institutions that helps create a critical mass, (4) Owning the narrative, and (5) Moral disengagement."
First, there are the organized attempts to cover up the record of past atrocities. The nearest successful example in the modern era is the 80 years of official denial by successive Turkish governments of the 1915–17 genocide against the Armenians in which some 1.5 million people lost their lives. This denial has been sustained by deliberate propaganda, lying and coverups, forging documents, suppression of archives, and bribing scholars.
The dictionary definition of cover-up at Wiktionary
Media related to Concealment at Wikimedia Commons