arse vs posterior

arse

noun
  • A person; the self; (reflexively) oneself or one's person, chiefly their body; (by extension) one's personal safety, or figuratively one's job, prospects, etc. 

  • A stupid, pompous, arrogant, mean or despicable person. 

  • Used in similes to express something bad or unpleasant. 

verb
  • To be silly, act stupid or mess around. 

posterior

noun
  • The hinder parts of the body. 

  • The probability that a hypothesis is true (calculated by Bayes' theorem). 

adj
  • Following in order or in time. 

  • Next to, or facing the main stem or axis. 

  • Relating to or denoting presentation of a fetus in which the rear or caudal end is nearest the cervix and emerges first at birth. 

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