clean up vs worsen

clean up

verb
  • To make an area or a thing clean; to pick up a mess; to tidy. 

  • To make a large profit; to win by a large margin, or to win a large amount, especially in gambling. Also clean house. 

  • To intervene in a fight between two players at low health and easily kill both of them or the winner. 

  • To become clean, handsome, smart in appearance, e.g. for a special occasion, especially when it is out of character to be seen as such. 

worsen

verb
  • To make worse; to impair. 

  • To become worse; to get worse. 

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