roust vs unburden

roust

verb
  • to rout out of bed; to rouse 

  • to arrest 

  • To harass, to treat in a rough way. 

  • to drive strongly 

noun
  • A strong tide or current, especially in a narrow channel. 

unburden

verb
  • To free from burden, or relieve from trouble. 

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