stonehard vs sturdy

stonehard

adj
  • Hard as stone 

sturdy

adj
  • Of firm build; stiff; stout; strong. 

  • Resolute, in a good sense; or firm, unyielding quality. 

  • Solid in structure or person. 

noun
  • A disease caused by a coenurus infestation in the brain of an animal, especially a sheep or canid; coenurosis. 

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