plateau vs prostrate

plateau

verb
  • (of a varying quantity) To reach a stable level after a period of increase; to level off. 

noun
  • A comparatively stable level after a period of increase. 

  • A notable level of attainment or achievement. 

  • A largely level expanse of land at a high elevation; tableland. 

prostrate

verb
  • To overcome or overpower. 

  • To throw oneself down in submission. 

  • To lie flat or face-down. 

  • To cause to lie down, to flatten. 

adj
  • Lying flat, face-down. 

  • Physically incapacitated from environmental exposure or debilitating disease. 

  • Trailing on the ground; procumbent. 

  • Emotionally devastated. 

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