BOB vs phallus

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. 

phallus

noun
  • A representation of an erect penis symbolising fertility or potency. 

  • A penis, especially when erect. 

  • The signifier of the desire of the Other, and the signifier of jouissance. 

  • A similar erectile sexual organ present in the cloacas of male ratites. 

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