Wiktionary
n. An address book, especially one in which the details of one's lovers are recorded
Wikipedia
Little Black Book is a 2004 satirical comedy film directed by Nick Hurran, and starring Brittany Murphy and Ron Livingston in the main roles. Holly Hunter, Julianne Nicholson, Josie Maran, Rashida Jones and Kathy Bates all serve in supporting roles. Carly Simon makes a cameo appearance at the end of the film.
"Little Black Book" is the fourth and final single from Belinda Carlisle's Live Your Life Be Free album, released in 1992 (See 1992 in music). It was the first ever released single co-written by Carlisle. Future Grammy-winner Sheryl Crow sang background vocals under the name "Cherryl Crowe".
Usage examples of "little black book".
Four hours of studying memo slips, ledgers and little black book notations and I trusted myself on a reconstruction.
We know what she was, and we'll get it confirmed a couple of hundred times by the men in that little black book.
He got out his little black book and was picking phone numbers when a messenger arrived.