canvass vs secret ballot

canvass

noun
  • A scrutiny of the votes cast in an election to reject irregular votes; also, a tally, audit, and certification of votes. 

  • A seeking or solicitation, or determination, of support or favourable votes in a forthcoming election or poll. 

  • A seeking or solicitation of donations, information, opinions, support, etc. 

verb
  • To seek the support of voters or a constituency in a forthcoming election or poll; to campaign. 

  • To thoroughly examine or investigate (something) physically or by discussion; to debate, to gather opinion, to scrutinize. 

  • To seek the support of (voters or a constituency) in a forthcoming election or poll through personal solicitation or public addresses. 

  • To scrutinize (the ballot in an election or the votes cast) and reject irregular votes; also, to challenge or dispute (an election result). 

  • To seek or solicit donations, information, opinions, support, etc. from (people or a place) 

  • To debate, to discuss. 

  • To seek or solicit donations, information, opinions, support, etc.; to conduct a survey. 

secret ballot

noun
  • The voting system involving ballots available only at official polling places, prepared at public expense, containing the names of all candidates, and marked in secret at the polling places. 

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