forgo vs refrain

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. 

refrain

verb
  • To stop oneself from some action or interference; to abstain. 

  • To abstain from (food or drink). 

noun
  • The chorus or burden of a song repeated at the end of each verse or stanza. 

  • A much repeated comment, complaint, or saying. 

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