A "private diary" refers to a personal journal or notebook where someone can write down their thoughts, feelings, and experiences without intending to share them with others. It is a place to keep secrets and express oneself freely. Full definition
Ministers could be forced to release the contents of private diaries — with former health secretary... (totalpolitics.com)
While Clara spends her nights turning a buck at seedy strip clubs and feeding on the occasional overly friendly client, Clara lives a life of solitude that she records in private diaries. (indiewire.com)
Murphy draws material from primary sources, such as private diaries, newspapers, and books, to give insight into the political, social, and cultural challenges of the yellow fever epidemic. (ala.org)