hardy vs surd

hardy

adj
  • Impudent. 

  • Having rugged physical strength; inured to fatigue or hardships. 

  • Able to survive adverse growing conditions. 

  • Brave and resolute. 

noun
  • Anything, especially a plant, that is hardy. 

  • A blacksmith's fuller or chisel, having a square shank for insertion into a square hole in an anvil, called the hardy hole. 

surd

adj
  • Involving surds, or irrational numbers; not capable of being expressed in rational numbers. 

  • unvoiced; voiceless 

noun
  • An irrational number, especially one expressed using the √ symbol. 

  • A voiceless consonant. 

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