1. a register listing persons that have committed offences against morality, etc.:
- The German government was in a position to blackmail 47,000 prominent British “perverts” whose names figured in a “black book.”
Cf.: be in someone’s black books—be out of favor with a person:
- Beatrice managed to leave a very uncomfortable impression upon me and it was clear that I was in her black books again.
2. an official book offering special information:
- Rules relating to naval affairs are still preserved in the black book of the admiralty.
little black book—
1. a book containing the names of acquaintances, potential dates, partners, etc.:
- I’ve got a nice collection in my little black book.
2. a book for recording personal or private information:
- Evans kept a note of his expenditure in a little black book.
Note: Neither expression correlates in meaning with the phrase black-letter book—a book printed in the old heavy Gothic style of type:
- She saw Sir John seated by the fireplace, reading out of a great black letter book.