hold on vs stand firm

hold on

verb
  • To grasp or grip firmly. 

  • To remain loyal. 

  • To persist. 

  • To keep; to store something for someone. 

  • Wait a short while. 

stand firm

verb
  • To resist assault or pressure. 

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