BOB vs edging

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. 

edging

noun
  • The sexual technique of maintaining a high level of sexual arousal for an extended period of time without reaching orgasm. 

  • A technique involving the placement of the edge of the climbing shoe on a sharp hold. 

  • The operation of shaping or dressing the edge of anything, as of a piece of metal. 

  • Anything that forms, defines, or marks the edge of something. 

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