inadequate vs subnormal

inadequate

noun
  • An individual who is inadequate. 

adj
  • Not adequate; not fit for the purpose 

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. 

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