disuse vs forgetfulness

disuse

noun
  • The state of not being used; neglect. 

verb
  • To cease the use of. 

forgetfulness

noun
  • Failure to bear in mind; careless omission; inattention. 

  • Loss of remembrance or recollection; a ceasing to remember; oblivion. 

  • The quality of being forgetful; proneness to let slip from the mind. 

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