terrain vs tract of land

terrain

noun
  • An area of land or the particular features of it. 

  • The surface of the earth; the ground. 

  • A single, distinctive rock formation; an area having a preponderance of a particular rock or group of rocks. 

tract of land

noun
  • Used other than figuratively or idiomatically: see tract, of, land. 

  • A woman's breast. 

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