skyline vs skysill

skyline

noun
  • The horizontal silhouette of a city or building against the sky. 

  • A panel on the front page of a newspaper outlining some of the features to be found inside. 

  • The line at which the earth and sky meet. 

  • A path of movement, especially military movement, producing a silhouette above terrain features visible from the location of likely observers. 

verb
  • To filter by means of the skyline operator. 

  • To outline something against the sky. 

skysill

noun
  • Horizon. 

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