etiolated vs monotone

etiolated

adj
  • Lacking in vigour; anemic, feeble. 

  • Of a plant: intentionally grown in the dark. 

  • Of an animal or person: having an ashen or pale appearance; also, haggard or thin; physically weak. 

  • Of a plant or part of a plant: pale and weak because of sunlight deprivation or excessive exposure to sunlight. 

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. 

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