former vs posterior

former

adj
  • Previous. 

  • First of aforementioned two items. Used with the, often without a noun. 

noun
  • An object used to form something, such as a template, gauge, or cutting die. 

  • Someone who forms something; a maker; a creator or founder. 

  • Someone in, or of, a certain form (class). 

posterior

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. 

noun
  • The hinder parts of the body. 

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

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