extensive vs massive

extensive

adj
  • Having a great extent; covering a large area; vast. 

  • Serving to extend or lengthen; characterized by extension. 

  • Having a combined system entropy that equals the sum of the entropies of the independent systems. 

  • Considerable in amount. 

massive

adj
  • Very large in size or extent. 

  • Very large or bulky and heavy and solid. 

  • Outstanding, beautiful. 

  • Not having an obvious crystalline structure. 

  • Having any mass. 

  • Having a large mass. 

  • To a very great extent; total, utter. 

  • Of particularly exceptional quality or value; awesome. 

  • Affecting a large portion of the body, or severe. 

  • Homogenous, unstructured. 

noun
  • A group of people from a locality, or sharing a collective aim, interest, etc. 

  • A homogeneous mass of rock, not layered and without an obvious crystal structure. 

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