poltroon vs retromingent

poltroon

adj
  • Cowardly. 

noun
  • An ignoble or total coward; a dastard; a mean-spirited wretch. 

retromingent

adj
  • Cowardly. 

  • That urinates backwards; also used of such urination. 

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