searchlight vs top light

searchlight

noun
  • The light from the above source. 

  • A light source that projects a bright beam of light in any direction, generally for military use. 

verb
  • To scan or sweep across like a searchlight. 

top light

noun
  • Light from above; toplighting. 

  • Any glazing above a main window, partition or door 

  • A skylight. 

  • The upper (and usually smaller) part (casement) of a window, often hinged a the top 

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