groaning vs keening

groaning

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

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

  • That groans. 

keening

noun
  • An unpleasant wailing sound. 

  • Intense mournful wailing after a death, often at a funeral or wake 

adj
  • Sharp, shrill, especially of a sound. 

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