cumshaw vs throw over

cumshaw

verb
  • To give or make a present to. 

noun
  • A gratuity or tip as thanks for a service 

throw over

verb
  • To discard or give up (a plan or project, etc.). 

  • To end a romantic/sexual relationship with. 

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