prognostic vs warning sign

prognostic

noun
  • A sign by which a future event may be known or foretold. 

  • prognosis 

  • One who predicts the future. 

  • A prediction of the future. 

adj
  • Of, pertaining to or characterized by prognosis or prediction. 

warning sign

noun
  • A sign that indicates a danger, for example to vehicles on a road or of hazardous chemicals. 

  • An indication that someone or something is in danger or at risk 

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