former vs one time

former

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

  • Previous. 

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). 

one time

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