hibernal vs icy

hibernal

adj
  • Of or pertaining to winter; brumal or hiemal 

icy

adj
  • Pertaining to, resembling, or abounding in ice; cold; frosty. 

  • To be wearing an excessive amount of jewelry, especially of the high-quality and expensive kind. 

  • Characterized by coldness of manner; frigid; cold. 

  • Covered with ice, wholly or partially. 

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