forgo vs sign off

forgo

verb
  • To refrain from, to abstain from, to pass up, to withgo. 

  • To let pass, to leave alone, to let go. 

  • To do without, to abandon, to renounce. 

sign off

verb
  • To log off; to stop using a computer, radio, etc., especially to stop talking. 

  • to give one's official approval to something for which it is needed 

  • To cease broadcasting a radio or television signal, usually at the end of a broadcasting day. 

noun
  • The closing of a radio or television station's studios and cessation of the broadcasting signal, usually overnight. 

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