alert vs fire alarm

alert

noun
  • An alarm. 

  • A state of readiness for potential combat. 

  • A notification of higher importance than an advisory. 

adj
  • Attentive; awake; on guard. 

verb
  • To give warning to. 

fire alarm

noun
  • The sound or other warning made by a fire alarm. 

  • An electromechanical or electronic bell, klaxon, chime, horn, speaker, strobe light or other device which warns people in a building of a possible fire or other condition requiring evacuation. 

  • An emergency response to a fire by the fire department with manpower and equipment. 

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