subnormal vs unutterable

subnormal

noun
  • A person whose abilities are less than normal. 

  • That part of the axis of a curved line which is intercepted between the ordinate and the normal. 

adj
  • denormal 

  • Less than normal. 

unutterable

noun
  • Something which is unutterable (incapable of being physically spoken, incapable of being articulated or expressed, etc.). 

adj
  • Not utterable; incapable of being physically spoken or voiced; unpronounceable. 

  • Not allowed to be spoken; taboo, unspeakable. 

  • Incapable of being articulated or expressed; indescribable, inexpressible. 

  • Extremely bad or objectionable; unspeakable. 

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