sundown vs twilight

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. 

twilight

noun
  • The time when the sun is less than 18° below the horizon. 

  • Any faint light through which something is seen; an in-between or fading condition. 

  • The soft light in the sky seen before the rising and (especially) after the setting of the sun, occasioned by the illumination of the earth’s atmosphere by the direct rays of the sun and their reflection on the earth. 

  • The time when this light is visible; the period between daylight and darkness. 

adj
  • Pertaining to or resembling twilight; faintly illuminated; obscure. 

verb
  • To illuminate faintly. 

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