BOB vs vertical

BOB

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. 

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

vertical

adj
  • Of or pertaining to vertical markets. 

  • In a three-dimensional co-ordinate system, describing the axis z oriented normal (perpendicular, orthogonal) to the basic plane xy. 

  • In a two-dimensional Cartesian co-ordinate system, describing the axis y oriented normal (perpendicular, at right angles) to the horizontal axis x. 

  • Involving different vintages of the same wine type from the same winery. 

  • Standing, pointing, or moving straight up or down; parallel to the local direction of gravity; along the direction of a plumb line; perpendicular to something horizontal. 

  • Of an interval: having the two notes sound simultaneously. 

noun
  • A vertical market. 

  • An individual slat in a set of vertical blinds. 

  • A vertical geometrical figure; a perpendicular. 

  • A vertical component of a structure. 

  • A vertex or zenith. 

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