danger signal vs flare

danger signal

noun
  • An indication that a potentially bad or dangerous situation could develop. 

  • A signal set at danger and showing a red light or other stop indication, which a train driver must not pass until it changes or until manually cleared past the signal by a dispatcher. 

flare

noun
  • A sudden eruption or outbreak; a flare-up. 

  • A type of pyrotechnic that produces a brilliant light without an explosion, used to attract attention in an emergency, to illuminate an area, or as a decoy. 

  • Bell-bottom trousers. 

  • The transition from downward flight to level flight just before landing. 

  • A low fly ball that is hit in the region between the infielders and the outfielders. 

  • A route run by the running back, releasing toward the sideline and then slightly arcing upfield looking for a short pass. 

  • A breakdance move of someone helicoptering his torso on alternating arms. 

  • A source of brightly burning light or intense heat. 

  • The increase in width of most ship hulls with increasing height above the waterline. 

  • A flame produced by a burn-off of waste gas (flare gas) from a flare tower (or flare stack), typically at an oil refinery. 

  • A widening of an object with an otherwise roughly constant width. 

  • An inflammation such as of tendons (tendonitis) or joints (osteoarthritis). 

  • A sudden bright light. 

verb
  • To shine out with a sudden and unsteady light; to emit a dazzling or painfully bright light. 

  • To cause to burn; in particular, to burn off excess gas (flare gas). 

  • To open outward in shape. 

  • To blaze brightly. 

  • To shine out with gaudy colours; to be offensively bright or showy. 

  • To (operate an aircraft to) transition from downward flight to level flight just before landing. 

  • To suddenly happen or intensify. 

  • To suddenly erupt in anger. 

  • To cause inflammation; to inflame. 

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