pocketknife vs shiv

pocketknife

noun
  • A knife with blades or tools that the user can fold or retract into its handle, and of a size small enough for carrying safely and handily in a pocket, especially when suited to heavier duty uses or ad hoc applications outdoors or in workshops. 

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 pocketknife and shiv occurred in a corpus of books? (source: Google Ngram Viewer )