flyover vs pop-up

flyover

noun
  • A low-level flight, especially of military aircraft, of a ceremonial nature; a flypast (British). 

  • A road or railway that passes over another, allowing routes to cross without interruption. 

  • A high-level overpass built above main overpass lanes. 

pop-up

noun
  • A pop-up ball: a ball that has been hit to a considerable height above the infield or the shallow outfield; a pop fly. 

  • A folded paper element which pops up from a book, greeting card, etc. 

  • A business that quickly pops up, such as a temporary restaurant. 

  • A pop-up advertisement; an advertisement that is triggered to appear on a computer screen when an Internet user accesses a particular web page. 

adj
  • Opening out to form a three-dimensional structure when the page of a book is opened. 

  • Coming into view suddenly from a concealed position. 

  • Employing the cold launch technique. 

  • Operating or existing for a brief period only; temporary. 

How often have the words flyover and pop-up occurred in a corpus of books? (source: Google Ngram Viewer )