black book
Plural
black books
2
a list with contact information of people whom one secretly communicates with
The idiom "black book" originated from the practice of maintaining a personal record or ledger, traditionally bound in black covers, in which individuals would note down the names and contact information of people they wished to keep private or secret communications with. Over time, the phrase "black book" has come to symbolize a list of individuals with whom someone maintains hidden or discreet connections, often implying secretive or illicit activities.
- The politician's black book contained the names of influential donors who preferred to remain anonymous.
- The CEO's assistant was entrusted with the company's black book, which held the contact details of clients involved in discreet business transactions.
- The private investigator's black book was filled with the names of informants and confidential sources who provided valuable information.
- The celebrity's black book was rumored to include the numbers of high-profile individuals in the entertainment industry with whom they maintained secret relationships.
- The journalist's black book was an invaluable resource, containing the contact information of whistleblowers and insiders who disclosed sensitive information.