monotone vs upstairs

monotone

adj
  • Having a single unvaried pitch. 

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

verb
  • To speak in a monotone. 

noun
  • A piece of writing in one strain throughout. 

  • A single unvaried tone of speech or a sound. 

upstairs

adj
  • Pertaining to a pitched ball that is high, and usually outside the strike zone. 

  • Located on a higher floor or level of a building. 

adv
  • Up the stairs; on a higher floor or level. 

  • In heaven, especially with regard to where a deity might be found. 

  • In the brain or mind. 

noun
  • A woman's breasts. 

  • An upper storey. 

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