former vs predecessor

former

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

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

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

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

  • Previous. 

predecessor

noun
  • One who precedes; one who has preceded another in any state, position, office, etc.; one whom another follows or comes after, in any office or position. 

  • A model or type of machinery or device which precedes the current (or later) one. Usually used to describe an earlier, outdated model. 

  • A vertex having a directed path to another vertex 

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