charnel vs polyandrium

charnel

noun
  • A repository for dead bodies. 

  • Part of a helm, now usually identified as the hinge (near the neck) by which the helm was secured to the breastplate. 

  • A chapel attached to a mortuary. 

adj
  • Of or relating to a charnel, deathlike, sepulchral. 

polyandrium

noun
  • A polyandrion. 

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