encourage vs thrash

encourage

verb
  • To spur on, strongly recommend. 

  • To mentally support; to motivate, give courage, hope or spirit. 

  • To foster, give help or patronage 

thrash

verb
  • To beat mercilessly. 

  • To defeat utterly. 

  • To extensively test a software system, giving a program various inputs and observing the behavior and outputs that result. 

  • In computer architecture, to cause or undergo poor performance of a virtual memory (or paging) system. 

  • To move about wildly or violently; to flail; to labour. 

  • To thresh. 

noun
  • A beat or blow; the sound of beating. 

  • thrash metal 

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