feedforward vs hold on

feedforward

verb
  • To respond in advance 

noun
  • An anticipatory response to expected changes in the environment of a system 

hold on

verb
  • To remain loyal. 

  • To grasp or grip firmly. 

  • To persist. 

  • To keep; to store something for someone. 

  • Wait a short while. 

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