hefty vs mountainous

hefty

adj
  • Large. 

  • Heavy, strong, vigorous, mighty, impressive. 

  • Strong; bulky. 

  • Heavy, weighing a lot. 

  • Possessing physical strength and weight; rugged and powerful; powerfully or heavily built. 

mountainous

adj
  • Resembling a mountain, especially in size; huge; towering. 

  • Very difficult. 

  • Having many mountains; characterized by mountains; of the nature of a mountain; rough (terrain); rocky. 

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