estimation vs viewport

estimation

noun
  • The amount, extent, position, size, or value reached in an estimate. 

  • The process of making an estimate. 

  • Esteem or favourable regard. 

viewport

noun
  • A typically rectangular region representing the range or area currently visible (within a window, screen, etc.). 

  • A viewing window. 

verb
  • To clip (an image or region) so that it fits in a viewport. 

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