herald vs omen

herald

verb
  • To greet something with excitement; to hail. 

  • To proclaim or announce an event. 

noun
  • A harbinger, giving signs of things to come. 

  • A handbill consisting of an advertisement. 

  • An official whose speciality is heraldry, especially one between the ranks of pursuivant and king-of-arms. 

  • A messenger, especially one bringing important news. 

  • A moth of the species Scoliopteryx libatrix. 

omen

verb
  • To be an omen of. 

  • To divine or predict from omens. 

noun
  • A thing of prophetic significance. 

  • Something which portends or is perceived to portend either a good or evil event or circumstance in the future, or which causes a foreboding; a portent or augury. 

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