buttock vs starboard

buttock

noun
  • The convexity of a ship behind, under the stern. 

  • Each of the two large fleshy halves of the posterior part of the body between the base of the back, the perineum and the top of the legs. 

starboard

noun
  • The righthand side of a ship, boat or aircraft when facing the front, or fore or bow. Used to unambiguously refer to directions according to the sides of the vessel, rather than those of a crew member or object. 

  • One of the two traditional watches aboard a ship standing a watch in two. 

verb
  • To put to the right, or starboard, side of a vessel. 

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