boiling vs estival

boiling

adj
  • Of the weather: very hot. 

  • Of a thing: extremely hot or active. 

  • Of a person: feeling uncomfortably hot. 

  • That boils or boil. 

adv
  • Extremely 

noun
  • An animation style with constantly changing wavy outlines, giving a shimmering or wobbling appearance. 

  • The process of changing the state of a substance from liquid to gas by heating it to its boiling point. 

estival

adj
  • Of or relating to summer. 

  • Coming forth in the summer. 

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