poniard vs shiv

poniard

noun
  • A dagger typically having a slender square or triangular blade. 

verb
  • To stab with a poniard. 

shiv

noun
  • A knife, especially a makeshift one fashioned from something not normally used as a weapon (like a plastic spoon or a toothbrush). 

  • A particular woody by-product of processing flax or hemp. 

verb
  • To stab someone with a shiv. 

  • To stab someone with anything not normally used as a stabbing weapon. 

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