piteous vs pitiful

piteous

adj
  • Provoking pity, compassion, or sympathy. 

pitiful

adj
  • So appalling or sad that one feels or should feel sorry for it; eliciting pity. 

  • Of an amount or number: very small. 

adv
  • In a pitiful manner; pitifully; piteously; pathetically. 

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