indigestible vs thoughtless

indigestible

adj
  • Difficult to accept; unpalatable. 

  • Difficult or impossible to digest. 

noun
  • Anything that is difficult to digest. 

thoughtless

adj
  • Inconsiderate, inattentive. 

  • Lacking thought or consideration. 

  • Marked by or showing lack of due thought or care; careless. 

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