monotone vs oppressive

monotone

adj
  • Being, or having the salient properties of, a monotone function. 

  • Having a single unvaried pitch. 

noun
  • A piece of writing in one strain throughout. 

  • A single unvaried tone of speech or a sound. 

verb
  • To speak in a monotone. 

oppressive

adj
  • Tyrannical or exercising unjust power. 

  • Hot and humid of the weather. 

  • Burdensome or difficult to bear. 

  • Weighing heavily on the spirit; intense, or overwhelming 

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