Definition of "blue book"

blue book

noun
plural blue books
1. A book of statistics or almanac, usually published by an agency or as a trade publication.
  Quotations
  "I was the flail of the Lord up in those parts, I may tell you, though you won't find it in any Blue-book."
  1912, Arthur Conan Doyle, The Lost World […], London, New York, N.Y.: Hodder and Stoughton
2. Used other than figuratively or idiomatically: see blue,‎ book.