BOB vs flagging

BOB

noun
  • Vibrator (device designed to stimulate a woman's genitals). 

adj
  • Back-of-the-book; denoting those stamps in a catalogue that are not used for the payment of regular postage fees, and are displayed separately in the catalogue after that listing; the division between these two groups varies with the publisher. 

flagging

noun
  • Use of a handkerchief code or analogous display to signal sexual interests. 

  • A pavement or sidewalk of flagstones; flagstones, collectively. 

  • The skewing or bending of the upper part of a television picture due to imperfect synchronization of the video signal. 

  • The process by which something flags or tires. 

adj
  • Becoming tired or less dynamic; declining in strength; dwindling. 

How often have the words BOB and flagging occurred in a corpus of books? (source: Google Ngram Viewer )