check mark vs signifier

check mark

noun
  • A mark (✓) made to indicate agreement, correctness or acknowledgement. 

  • In long jump, javelin and similar events, little mark alongside the runway which helps the athlete to set their steps just right for their performance. 

signifier

noun
  • Something or someone that signifies, makes something more significant or important. 

  • The sound of a spoken word or string of letters on a page that a person recognizes as a sign. 

  • A card representing a querent, question, or situation. 

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