cockcrow vs sundown

cockcrow

noun
  • The time of day at which the first crow of a cockerel is heard; dawn or daybreak; first light 

sundown

noun
  • Sunset. 

  • A hat with a wide brim to shade the eyes from sunlight. 

verb
  • to experience an episode or an onset of some detrimental mental condition like agitation, anxiety, hallucination or dementia, daily at nightfall. 

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