flatland vs pampas

flatland

noun
  • Synonym of plain: land of relatively constant altitude, usually exclusive of forests, deserts, and wastelands. 

  • An urban region with many flats or apartments to rent. 

pampas

noun
  • The extensive plains of South America south of the Amazon. 

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