A cover-up is an attempt, whether successful or not, to conceal evidence of wrongdoing, error, incompetence or other embarrassing information. In a passive cover-up, information is simply not provided; in an active cover-up, deception is used.

What does it mean to cover-up someone?

: a planned effort to hide a dishonest, immoral, or illegal act or situation. : an action or a way of behaving that is meant to prevent people from knowing about something. See the full definition for cover-up in the English Language Learners Dictionary. More from Merriam-Webster on cover-up.

What does Unexplain mean?

: not explained or accounted for an unexplained error an unexplained delay.