secret ballot vs slate

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. 

slate

noun
  • A list of affiliated candidates for an election. 

  • An artificial material resembling slate and used for the same purposes. 

  • A record of money owed. 

  • A tablet computer. 

  • A thin plate of any material; a flake. 

  • A fine-grained homogeneous sedimentary rock composed of clay or volcanic ash which has been metamorphosed so that it cleaves easily into thin layers. 

  • The bluish-grey colour of most slate. 

  • A chalkboard, sheet of slate for writing on with chalk or with a thin rod of slate (a slate pencil) formerly commonly used by both students and teachers in schools. 

  • A roofing-tile made of slate. 

verb
  • To cover with slate. 

  • To schedule. 

  • To criticise harshly. 

  • To set a dog upon (a person). 

  • To anticipate or strongly expect. 

  • To nominate, appoint, or designate. 

adj
  • Having the bluish-grey/gray colour of slate. 

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