get up vs let up

get up

verb
  • To criticise. 

  • To go towards the attacking goal. 

  • To materialise; to grow stronger. 

  • To move from a sitting or lying position to a standing position; to stand up. 

  • To rise from one's bed (often implying to wake up). 

  • To bring together; to amass. 

  • To gather or grow larger by accretion. 

  • To move in an upward direction; to ascend or climb. 

  • To dress in a certain way, especially extravagantly. 

  • To annoy. 

let up

verb
  • To cease or stop (doing something intense). 

  • To cease or stop. 

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