oppressive vs smouldering

oppressive

adj
  • Hot and humid of the weather. 

  • Tyrannical or exercising unjust power. 

  • Burdensome or difficult to bear. 

  • Weighing heavily on the spirit; intense, or overwhelming 

smouldering

adj
  • Burning slowly, producing smoke but no flame. 

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

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