penitentiary vs stockade

penitentiary

noun
  • A state or federal prison for convicted felons; (broadly) a prison. 

  • A priest in the Roman Catholic Church who administers the sacrament of penance. 

adj
  • Of or relating to penance; penitential. 

  • Of or relating to the punishment of criminals. 

stockade

noun
  • a military prison 

  • an enclosure protected by a wall of wooden posts 

verb
  • To enclose in a stockade. 

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