asperous vs groaning

asperous

adj
  • rough, rugged, uneven 

  • bitter, cruel, severe 

groaning

adj
  • Heavily laden, as if to creak under the strain. 

  • That groans. 

noun
  • A low sound associated with extended suffering, sorrow, and toil. 

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