fire alarm vs lesson

fire alarm

noun
  • 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. 

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

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

lesson

noun
  • Something that serves as a warning or encouragement. 

  • A learning task assigned to a student; homework. 

  • A severe lecture; reproof; rebuke; warning. 

  • A section of learning or teaching into which a wider learning content is divided. 

  • A section of the Bible or other religious text read as part of a divine service. 

  • Something learned or to be learned. 

  • An exercise; a composition serving an educational purpose; a study. 

verb
  • To give a lesson to; to teach. 

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