lamppost vs top light

lamppost

noun
  • The pole that holds up a light so it can illuminate a wide area, such as holds up a streetlight. 

  • A tall, thin person. 

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 lamppost and top light occurred in a corpus of books? (source: Google Ngram Viewer )