precipitant vs smouldering

precipitant

noun
  • A substance that forms a precipitate when added to a solution. 

adj
  • Sudden or unexpected. 

  • That falls headlong, or causes a headlong fall. 

  • Rash or impulsive. 

  • That causes precipitation. 

smouldering

noun
  • The act by which something smoulders; residual heat. 

adj
  • Burning slowly, producing smoke but no flame. 

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